On Oahu, who is a good mechanic to rebuild F-body 9 and 10 bolt rear ends?

My dang back is acting up again, and although I'd like to dig into my son's '92 Z28 we just brought back from AZ to change the 10-bolt bearings, I might not be physically able to do so.

Can someone recommend a good mechanic?

Thanks,
Ed

 

Well I'm no mechanic, but if you could sit down and walk me through it I'm sure I could help you get it done. I gotta do some stuff with my 10 bolts too, so would be a good learning experience. Lemme know.

 

Ace Transmissions in Wahiawa may be able to help, give them a call. Walt's Performance in Waipahu, also, depends on how far you want to travel. (That, or stick a Ford nine-inch in it.)

 

Randy and Clayton at ace are top notch...

Walt and crew are also...

 

Co-worker brought them up (Dave Coburn). Walt was going to rebuild mine, but recommended that I stick some posi-fluid in it before I commit to a rebuild. Good advice, too, my annoying problems went away.

 

Wow, that's really generous of you and I really appreciate it!

It would also be a learning experience for me, as I've not overhauled differentials before, but darn, physically I'm really useless right now.

Wahiawa is preferable to Waipahu, so guess I'll get in touch with Randy and Clayton at Ace Transmissions. Besides, working at Schofield makes it easy to get over there.

Thanks guys, your advice is really valuable to me, as I mostly do all my own work on the Camaros and would hate to let some bozo lay a wrench on them.

 

The entire rear is very easy to do. There are only a couple of specialty tools that you need. If you have any questions or need a hand, let me know.

Scott

 

Ed, is there anything wrong with the rear now?

If you are rebuilding just because "it's about time to," there are a few things that you can do to service them without really taking much apart so you can 'see where it's at.'

I'd recommend flushing the oil and maybe replace the axle bearings then roll a pattern to see how the other stuff specs out. As long as the pattern is good and there's no noise, there's not much that needs to be done.

 

I need to redo 2 10 bolts. First will be the continuous rotation of exploding 26 spline 10 bolts for drifting. Gonna have like 3 of em in storage so I can swap em faster when they break (I'm sure they will break). So I definately need to learn how to do this myself. I gotta install a mini spool, 3.73 gearset, c-clip eliminator kit, change the studs to better studs, and modify the flange for the brakes to accept LS1 rears. The second 10 bolt will be the 28 spline 10 bolt from my 91 Z28. I wanna swap over the posi and brakes from an '00 SS rearend. So gotta swap the posi, put in a 4.10 gearset, and modify the brake flange to accept LS1 brakes. You think this is do-able in someones home garage Scott? I guess I gotta take it somewhere to get the flange cut.

 

For pinion bearings, you'll need a press. Other than that, it's all smaller tools. If you're changing gear sets, the pinions might have the bearings preinstalled.

For the c-clip eliminator, I think you need to drill or do something to the backing plate flange.... I need to see it again to remember. I've never done that one yet.

You need something to hold the companion flange while you tighten the (companion flange/drive pinion) nut. You can make something out of a long steel plate and a drill. Also need a bearing remover for the axle bearings.

A dial indicator is useful for the blacklash, but you don't need it. That can be done by feel or with the contact pattern. A little in-lbs beam-type torque wrench is needed for the preload.

I'm not sure which parts are the weakest, but if it's one or two things breaking all the time, you can either put a stronger part in or you'll just get really good at setting them up!

I've never done a 9 bolt or 7.5" yet. I've done the 8.5" 10-bolt and a couple 9"s so far.

Scott

 

Sounds like I gotta go get some more tools. I'm pretty sure the weakest link for the drifting 10 bolt will be the axles themselves. I know there are aftermarket axles out there, but for the price of the aftermarket axles I can get 3-4 more 10 bolts hahahaha. I guess I should wait and see if they break right away or not. For all I know, they might actually hold up since drifting involves more slip than grip, not hard on the rearend like launching at the 1/4 with slicks or anything. I'm kinda giving up on the 9 bolts before I even start because of the prices of the aftermarket parts. Stock for stock I like the 9 bolts, but if you want beyond stock and budget prices, I think the 10 bolt is the way to go.

The only thing I'm really worried about is trying to do the c-clip eliminator, and modify the flange for LS1 type rear brakes. Not sure if both of them will work together or not, but both are important. The eliminator kit will keep the axles from flying out if they do break, and the LS1 type brakes gives me alot more options as far as aftermarket rear brakes (going custom).

 

During our trip on the mainland, when Martin and I left Prescott, AZ and headed to Kingman, AZ, a very annoying drivetrain vibration became apparent between 70-80 mph. I took it to a GM dealer in Kingman and wasted $59 to have them tell me a rubber bushing needed replacing [yeah, I know that...] and it was obviously not that causing the problem. I was leaning more toward the engine vibration damper or the torque converter, but I took the car to a specialty drivetrain race shop in Kingman and those parts checked out ok. However, the rear pinion seal was leaking so had a new one installed. About 1,000 miles later in the trip, the car developed a very loud whine and grinding from the rear and we barely made it to Long Beach to put the car on a Matson ship. My theory is that the pinion nut was reinstalled too tight, which put excessive pressure on the pinion bearing, causing it to gall and fail.

I'll know more next week after I get some estimates.

Working on it is something I'd really like to do, but a lifetime of excess finally caught up with my back -- when I tried to get into my IROC this a.m. to go to work, my lower back spazzed-out and I couldn't even get in the car ... a pinched nerve put me flat on the ground. Boy, that was painful. After spending the whole day at Kaiser I can only pop pills and watch tv laying down [tried for medical ganja but was denied].

If you're still willing to help, in another month or two I could use your brake expertise to install the 1LE front and rears on the IROC. By that time I'll also be able to bend over and pick up dropped tools without collapsing [heh]. I can use the lifts over at the Fort Shafter auto craftshop, so should be fairly easy.

Cheers,
Ed

 

I have 10 bolts...

I'll make you a deal Shawn... call me when you get a chance...

I need space...

 

Sounds Good!

 

pm sent

 

Ed, there's a simple way to check your pinion bearing preload but if you can't get to it, I guess it's time to make friends with a mechanic. A lift would be very useful for the rear or the brakes.

Shawn, I think your axle shafts will be okay for long hours of hard use, but it wouldn't hurt to keep spares. I don't recommend upgrading to expensive, stronger axle shafts because used good axles are cheap and plentiful. They are very easy to change if/when they break. Also, if you do upgrade, something else will probably break, and it'll probably be a bigger hassle to change. So, just stick to your plan.

I don't think using different brakes will interfere with the clip eliminators.

Scott

 

I called Randy in Wahiawa at Ace Transmissions and was quoted $400 parts and labor to overhaul the 10-bolt and install new bearings.

According to them, it takes about a day to complete.

Does this sound about right to you guys?

Cheers,
Ed

 

Once it's on a bench everything can be done in under 30 minutes. I don't know how necessary it is to remove it from the car. Just hanging the rear might provide enough room.

What exactly are they overhauling? Just replacing bearings and seals? Or replacing the ring and pinion?

If it's possible, have someone pop the cover off to inspect the gears for wear or damage and see if there's any metal in the oil. That way, you'll know if there are more parts to be replaced to add to the cost. More parts won't require any more work, so don't let them drive up the labor cost. If another part <i>does</i> require more labor, then whatever they're doin' ain't worth $400....

Scott

 

I believe at least one of the differential bearings is galled, it's easy to hear it grinding. The intent is to only pull the differential and replace the differential bearings. Don't know what else will be found that might be worn after 170K miles. Might be other worn parts.

$400 seems a bit high to me too, but certainly cheaper than GM, heh.

What would it cost if you were to do the job?

 

ouch, sorry to hear about your back Ed, I hope you get well soon... hehe too bad you didnt get that medicinal ganja ehehe wed all be at your house right now if ya did lol! In anycase, good luck with the rear-end overhaul!

 

Don't know, I'd have to price the parts. If it's only the bearings, it'd be parts + an hour or two. I don't know what my shop charges per hour, I can ask my prof if I can work on a rear since we're doin' auto trans now.

Pinion bearings - 2
Axle bearings - 2
Axle seals - 2
Possibly Pinion seal
Shims or Crush sleeve
Gasket (or rtv)

I'd recommend a new rear u-joint since it's coming off anyway, unless you have an aftermarket one with zerk fittings.

Before I commit to anything I'd have to get the go-ahead from my prof. How soon do you want this done?

 

Pinpointing your initial problem, however, might take a little longer unless it's something obvious. Most people blame the driveshaft (balance or u-joints).

If you were asking for me to personally to do the job (as opposed to at my class shop) then I'll do it for free labor if I can use the base's shop lift for a couple quick things on my car when we're done. However, if your vibration isn't an obvious problem, then we won't have any diagnostic tools.

The base shop loans all kinds of tools right? They've got presses and dial indicators et al, right?

 

Having an experienced friend walk us through the process is the best way, so we can benefit by learning! Also, "something for nothing" when someone else is getting greasy doesn't sit well with me, so at least $100 is on the table for your time. Parts might be $100-150, so that's a savings over the Ace estimate.

It might turn out that only the pinion bearing is bad and if the other two bearings are ok, don't see a need to change them. However the axle bearings should be changed, since they'll be out of the rear anyway. Yep, changing the driveshaft U-joints at the time is a good idea and maybe the rear brake pads since the calipers will be off the rotors.

Recommend we do the job at Fort Shafter craft shop, as it has a full range of tools for minor and major overhauls, including presses. We could get there about 9 a.m. Saturday, grab a rack, if there are delays, the car can be left overnight in a secure location.

We just got Hawaii plates and registration, and Martin is using the Astro van to get around, so no big hurry on doing the job. Sometime in the next couple of weeks would be good.

Unfortunately, the Army shop validates the registration and military ID of the driver to filter out unauthorized vehicles, so we couldn't work on your car in the facility unless my name was on the registration.

I can sponsor people to come inside and help with the work, so no problem if others want to see how the job is done.

Looks like you're getting some really good experience in your school! Just a little while longer and you'll be pulling in $40 an hour, heh.

 

Ouch ... going to back therapy twice a week isn't fun, at least it's an on-the-job injury [twisted back at work, didn't completely spazz out until a couple days later squirming into the car]. Heh, it would be pretty funny following the Dr's Orders couple times a day at work, toking-up in an authorized smoking area with all those G-men freaking-out, running amok waving machine guns...

 

Martin and Scott pulled the differential out of the '92 10-bolt today and it was determined that a new pinion gear is needed. Since we don't have an extra set of 10-bolt gears around , we're shopping for a replacement.

Anyone have a 3.23 ratio [or 3:42] 10 bolt 7.5 inch ring and pinion set in good shape available? If so please give a shout ASAP... Otherwise we'll have to get a set of Richmond Gears from Summit.

I and Martin learned a lot from Scott today, the sort of skills and knowlege unobtainable by just dropping off the car at "Yahoo's Garage."

Hope we can get the car finished and off the lift soon.

BTW, Scott, remember how hard the differential was to remove from the casing? It's more difficult getting it back in the case, and I don't know if the shop has a case spreader. So if you know one around that we could borrow for a day, it would make reinstallation a LOT easier.

 

dbl post -- FYI looks like attachments are not working right now

 

Don't worry about it. It's a piece of cake with a second pair of hands.

If you do buy a new ring and pinion, see if you can get some type of kit with the shims and paste. We will have to take all the measurements with new/different gears, but only one of those is "hard" to do.

Hopefully the shop will have some way to measure pinion depth. I'll see about the tiny torque wrench, and find out any tricks to set the pinion preload without a "flange bar."

Scott

 

We'll be getting a set of gears from Summit next week and also the $90 installation kit -- Grade 8 ring gear bolts, a cover gasket, bearings, seals, shims, marking compound, thread-locking compound, and silicone sealer.

Richmond Gear Ring and Pinion Set
RMG-4900451 $185.95

Richmond Gear Ring and Pinion Set
Ring and Pinion Ratio: 3.42:1
Cover Bolts: 10
Ring Gear Bolts: 10
Pinion Spline Count: 27
Carrier Series: 3
Ring Gear Rotation: Standard
Ring Gear Teeth: 41
Pinion Gear Teeth: 12
Ring Gear Diameter (in): 7.50
Pinion Shaft Diameter (in): 1.438
Gear, Ring and Pinion, 3.42:1 Ratio, GM, 7 1/2 in./7 5/8 in, 10-Bolt, 3 Series, Set

 

Scott -- the Richmond gears and install kit arrived today, so we can plan on reinstalling Sat morning, say 9 a.m.? Regards, Ed

 

You're red car was a 3.23, right?

The car will shift a bit earlier which will compensate for the higher rpm's so you'll probably get slightly better city gas milage at the cost of some highway milage.

Does that kit include all four bearings and races? That's a good price.

If you have a LARGE pipe wrench that'd be perfect for the proper pinion preload. Anything that will hold its grip and large enough to fit across the pinion flange.

I'll try to pick up a small torque wrench by friday.

Let me know when you want to finish this (if you still want me doin' the wrenchwork).

If you can find a new torque arm bushing, bring it along also.

Scott

 

You posted JUST before me. Sure thing.

Scott

 

Ooooh can I watch?

 

Sure. And bring a big-*** pipe wrench if you happen have one layin' around....

 

Changing from 3.23's to 3.42's will also improve the acceleration at bit.

Yes, the kit has everything, including the required new grade-8 ring gear bolts. I also printed the full set of adjustments in color.

I have a pipe wrench and will bring it along.

You're a good wrench, not your fault the hydraulic press work area has insufficient lighting...

Yes, I'll make sure the torque arm bushing is purchased.

Oh, and anyone else who wants to see how 10-bolt gears are setup, come on over to the Fort Shafter Auto Craft Shop on Shafter Flats. Military ID isn't needed to hang around and kibitz...

ed

 

A quick update -- we finally brought the 92 home today after more than a week on the rack. There is a nasty clunking sound coming from the rear and we hope it is an axle bearing. Saturday Martin and I will jack the car up and stethascope the axle tubes and rear housing... More will follow...

 

Here's a photo of Stew, Martin and Scott underneath the '92 Z28 considering the next move in the chess game of setting up the rear...

 

Hey, cool. Looks sort of like fun, actually... Did everything work out okay?

 

It only looks like fun in the photo 'cause you can't hear the groaning and cussing during the dozen reinstallations of the differential to setup the ring and pinion adjustment without the proper tools.

Scott came over to the house today to help locate the clunking noise, so we jacked-up the rear and spun the wheels while we prodded around listening with a stethoscope. Nothing conclusive yet, so we're taking it to Ace Transmission to have it fixed.

More will follow...

 

well hopefully you guys will be able to fix the problem without a lot of out of pocket expense..

Thats a nice lookin 92z there Ed, what kinda exhaust you got on her?

 

The '92 has dual cats and a flowmaster.

So far, working on the rear has cost about $600 in parts and services and three weeks downtime. The original part that failed was a $20 front pinion bearing.

 

well thats a little depressing... 20$ part the root of all problems hehehe... sickening almost, well at least this gives you an opportunity to learn a lot, as well as tend to any other problems down there.

 

Dang. That sucks, I'm sorry to hear that. This is for a ten-bolt, right? I shudder to think what a nine-bolt would run me...

 

It's typical that small parts are expensive to replace. Take for example, spinning a rod bearing and having to tear down the engine to replace it, or a clutch throwout bearing, which requires separating the engine and tranny -- both are small, cheap parts that take a lot of wrenching to fix. Well, at least I could do the clutch myself ... redoing the engine bearings I'll leave more experienced mechanics. Heh, I'd do a crate engine first!

 

How's the car coming along Ed. Did you bring it to Ace Transmission already?

 

They've been busy, I'm scheduled to call today and see if the Camaro can be dropped off today.

 

Well, this is getting ugly...

Dropped off the '92 at Ace on Monday, spoke with Randy and clearly communicated that loud clunking noises were coming from the rear end and that the ring and pinion and front pinion bearing were recently replaced -- and that the clunking noises did not exist prior to the work being done and in my opinion were probably being caused by components other than the differential.

"Find what's making the noise and make it stop," summed up the work request.

Randy called today, said the car was fixed, so Martin and I picked up the 92 after paying $333 parts and labor. All he did was reset the differential. He said the settings Scott did were just about right on target, but the pinion depth needed to be changed a bit. Ok, cool. When I asked about the clunking noise, he got evasive, saying stuff like, "new ring and pinions are always noisy, you might have a high spot or something on the gears that might wear down ... and then went on to say, there was a little bit of noise under certain loads, but it was OK."

When we drove the car home, the clunking noises were much louder than before, a clear statement that Randy either didn't look for the cause of the noise, or couldn't find it. I called him soon as we got home and asked what the hell was going on, why wasn't the cause of the clunking noise fixed -- we went round and round for a few minutes with him saying it's ok and I'm saying the car is undrivable -- when I insisted on bringing the car back to have it fixed, Randy ended the conversation by saying he'll refund the money and don't ever go back to his garage.

I feel like we both got screwed somehow -- I need the car to be fixed and he invested time and expertise in setting up the diff. But he was unable or unwilling to remedy the clunking noise, which was why the car was brought to him to repair in the first place.

Mechanics are professionals, just like IT network engineers, construction workers or doctors. Hey Doc, my finger is infected and the doc takes a look, prescribes medication and tells you to stop playing stinkfinger with strangers. If the infection doesn't go away, you go back to the doc for more treatment.

So to have Randy say "here's your money and take a hike" isn't the most professional response, sheesh. And I know him from racing a few sessions at Raceway Park, sigh.

I'll take the car around to some other garages for opinions/estimates, and at the same time evaluate other options, such as a complete rear swap, such as another Camaro stock 10-bolt, or a Moser, Strange, etc. For that I'll start another thread.

Sheesh, whatta hassle....

 

Try Walt's Performance in Waipahu. he said my clunking noise (when I turned) was either due to the posi being junk or that I needed posi additive. He said to add the fluid to it and if it didn't go away, I could go in and he'd tear it open. Added the additive like he suggested, and it worked. Called him up and said thanks. Bummer about them not able to fix the problem, at all... Who knows, it just might be somethign as simple as high spots. But getting a second opinion would be a good idea.

If that doesn't work, a new/replacement rear might be in order, like you said.

 

This is not a mere "clunking" when turnning ... it is very loud clanging that sounds like gears stripping...

 

Sorry to hear about your continuing problems. Especially since this still doesn't even fix your original vibration at speed.

I feel like it's my fault, but I'm not sure what it could be or how to make it stop since a pro rechecked all the specs. I doubt that it's the gears themselves, but you can check around the drivetrain forum for Richmond gear noise. Maybe they do need to be broken in....

I have a strange noise coming from the rear area of my '91 now. Sounds like a slinky being dragged or banged against metal. Checking it out on a lift tomorrow- I think it's brake related. My professor knows his stuff, and I'll try to get more info from him about your problem while he's lookin' over my car with me.

You can try takin' it to a good dealer. If they can positively ID the problem, you can take it to another shop if you know someone good. Did Randy replace the axle (or even side) bearings?

Scott

 

The origin of the rear end problem was my idiotic decision to replace the pinion seal in Kingman, AZ. 500 miles later the pinion race blew out, so no, it all started with me.

That's not to say the bearing and gear replacement here in Hawaii was without problem or excessive cost... $750 is a bit much for a learning experience. The additional $333 was returned by Randy, so the final cost hasn't gone higher, well yet anyway.

Tonight I put the 92 on jack stands to begin pulling the rear and I noticed the front pinion seal is leaking severely, sigh, but I will try to isolate the grinding before pulling the whole thing out.

Someday I'll put a couple grand into a nice 9-bolt or 12-bolt rear for the car, but just for loafing around Oahu any rear that accepts disk brakes will be good enough -- I'm actively looking for a replacement, so let me know if a 3rd or 4th gen rear is available.

Honestly, I learned that some jobs shouldn't be done without proper facilities, tools and an ironclad warranty -- that includes engines, trans and rears.

BTW, the noise is not "gear noise" made by a ring and pinion, it is something horribly gone wrong, possibly in the differential or axle.

More will follow...