my 84 ta has the 10 bolt rear end in it. i was told this would not hold up well to about 375hp and i will be using it on the track too so it will be getting pounded like a virgin on prom night. what would you guys recommend doing. are the 4th gens any stronger. im looking for a direct replacement or close to one. i dont have a welder to work with so if its needed then i wont be able to do it at least not for a while.

 

the only thing i can think of is a moser 9" houseing and axle combo...then piece together the rest...because you WILL grenade the stock 10 bolt, they really dont like slick...lol..trust me

 

A 4th gen diff is stronger than your 85 but only because it has 28 spline axles instead of 26 spline. You can upgrade your diff to use 28 spline axles and make it the same strength.

No matter what you do to a third or fourth gen diff, it will still have the tiny ring and pinion and that's what will fail first.

Your only option for a direct replacement is an aftermarket 12 bolt, 9" or Dana 60. None are cheap but that's the cost of making HP.

 

how would a rear end from a 2nd gen fit in there. i was told they were an 8.5 but not sure.

 

The only rear ends that will fit in your car are 3rd and 4th gen F body rear ends. NO others will bolt in. There are many after market choices. I like the Moser 12 bolt best.

 

Third and fourth gens are the only cars to use a torque arm suspension that will make it a direct swap. First and second gens use leaf springs. The hardest thing about trying to put some other diff under the car is finding a way to attach the torque arm. The aftermarket diffs have a mounting area to bolt it on.

An alternative is to change the rear suspension to something that eliminates the torque arm like ladder bars.

Run your 10 bolt until it breaks then decide how much is worth it. Factory cars have broken a 10 bolt on the street. I put a 10 bolt well into the 11's behind a BBC with no problems.

 

The fourth gens in very much stronger having the stronger ring gear and a Torsen LSD in there I do not know how complicated a swap that would be. A Currie 9inch that is a direct bolt in is about $1300 bucks.

 

1300 for a complete rear end or just the axles and the housing. i can get a 12 bolt from year one complete with brakes for 2500 i believe

 

A 4th gen has the same ring gear diameter as the 3rd gen so no upgrade there.

The spline count is better from about 90 on up.

You'll have an easier time with the rear end if you avoid really low ratios, particularly aftermarket sets.

They require smaller pinion gears that are ofcourse weaker than the originals. And anything dubbed a "race set" will be softer under load and has a better chance of failing on a street driven car.


So if or when you break your stock rear look for a 90-91 plus rearend, proabably a 3.xx carrier. stick with the factory ratios and tune your overall gearing with tire diameter, converter stall etc and try tuning the torque and power curves before trying lower ratios.

 

The only things that can be done to a 7.5" to up the strength are welding the tubes, 28-spline upgrade, aluminum stud girdle cover, and using a 2-series carrier with a 3.XX ratio (this is an unusual swap, but it provides a thicker ring gear, which will help strength somewhat)

These upgrades will help, but the biggest problem with these rear ends is the diameter of the ring gear (7.5") and the small shaft size of the pinion gear. They are the problem area, and the only thing that really cannot be changed.

The best thing to do is to upgrade to an aftermarket Ford 9" or a 12-bolt setup. Then you have a much bigger ring and pinion set (9.00" and 8.875") with a bigger axle (31, 33, 35 and 40 spline counts) and because of that, its incredibly strong.

 

$2900 bolt in ready to roll f body. Check the link to the right for Currie and search yourself. Nuts now that I mention it I can't see it anymore. I'll see if I can find it and post it up for you. OOps my mistake I went back and looked and that was the base for the housing and axles so my mistake. You are looking at $2800 to 3000k with 3.7 gears for a Detroit truetrac center and Ford explorer discs. Sorry about that. Just for being an *** I am going see if I can find you a deal on a package for it.

Found one Strange S60 (Dana 60) Package deal $2500 bucks everything included Detroit Truetrac, yokes bearings brakes etc. http://www.strangeengineering.net/catalog/index.html

Sorry about the $1300 thing I just glanced at it in the crate section and thought it was the ready to go price not the housing and axles price.

 

I'm looking for a better deal. I'm thinking at these prices a bone yard pick up differential with a new truetrac center and paying a machine shop to make weld up the necesssary brackets and what not for half as much even if you put in new bearings an seals too. Get the truck driveshaft with it for the proper yoke and bits and you could get out for $800 900 bucks.

 

Does anyone have a clear photo of a 9 bolt they can post up? I am emailing with some guys in Australia who deal in obscure BW parts and they want to see what it looks like.

 

You can go a relatively inexpensive route and buy the 9" housing package. You get a 9" housing that will be a direct bolt in and a pair of axles that will allow you to use your current GM brakes. All you need to do is provide a center section with gears, posi etc which you can pick up from a local auto wrecker. Get the housing package with 31 spline axles then find a center section that uses 31 spline axles. I wouldn't recommend using the smaller 28 spline Ford axles.

The 9" housing/axle package is around $1000. Throw in a junkyard center section for a couple of hundred bucks including oil and stuff and you can have a 9" under the car for less than $1500.

Maybe you won't find a factory posi, maybe you won't find a gear ratio to your liking but you can always upgrade later as funds are available. I managed to stumble across an old Bronco that was just put into the yard. It had a 31 spline posi with 4.11 gears. I had the proper tools with me at the time and I snatched up the center section in less than an hour. It cost me $100.

 

It really pays to buy a cheap welder and develope your skill.

I can get an entire rear end for $45 locally and narrowing the housing and fabricating the needed brackets is simple enough with even basic tools.

That leaves the driveshaft, axles (can usualy be shortened and resplined if it's substantialy cheaper than new ones) and the torque arm mount.


BTW about the F body 10 bolt, I have heard that the entire 90-96 B body production run suffered from an assembly line mistake that causes a lot of failures around 60xxx miles.

The cover gasket installed was wrong and didnt have the holes needed to allow oil to pass to the bearings at the end.

I havent heard of that happening with the F body or other cars but I'm wondering if anyone has run into this?

 

I have never heard of that with any GM rear ends. There are no gaskets in a 10-bolt that I can think of. Just the cover gasket, two axle seals, and the pinion seal. There are no internal gaskets or seals...?

 

if im going to make my own rear end which car/truck should i get it out of. am i looking for a special bolt pattern on the cover?

 

It's going to cost you more than buying an aftermarket diff.

Depending on what diff you plan on using, you don't have many options. Using a non GM diff means converting brake systems and wheel bolt patterns. Finding a diff the proper width isn't easy. A third gen diff is narrow compared to most other diffs. Then there's the problems of suspension. Because of the third gen's torque arm suspension, there's a lot of fabrication required to make it work with another diff or to replace the suspension with something else.

Providing you can find a diff that will work, by the time you're done fabricating and changing things to make it work, an aftermarket diff would have been easier and cheaper.

Everyone will spend lots of money on a high HP engine but nobody wants to spend money on the rest of the driveline to handle the extra power.

 

What diff is a camaro rear end narrow compared to? they are about 63 inches from drum to drum, which makes them wider than most full size cars, and only slighlty narrower than a full size truck.
A second gen camaro rear end is about 1 inch narrower, only a half inch per side, which works out well for me with wide tires. The brakes will work, and the bolt pattern is the same. Your options are an 8.5 10 bolt, which is the most common, or a 12 bolt. The 8.5 ten bolt is a fairly stout peice, at least in comparison to a 7.5!

That covers the width, but the tourqe arm, that is another story, it can be fabricated, but you need an experienced cast iron welder to do it, it is not that it is not possible, but welding cast is not for the faint of heart, and will fail if not done properly.

When I installed my second gen 8.5, it was easy, due to my using lakewood lift bars and not needing a tourqe arm, but you will find a lot of negative opinions on these bars on this forum. I have used them for five years with great results and no problems, but not everyone has been so lucky.

Here is the link to my post on my 8.5 install.
https://www.thirdgen.org/forums/fabr...5-10-bolt.html

 

where did you get your lakewood bars, how do you install them, part number, price... i think i will go with the 8.5 because my engine should put out a max of 425 at the flywheel with an auto trans so it should take out a lot of the shock and i can get a complete rear from the local u pull it for 50 bucks. plus any pics of your rear setup?

 

You can get them from summit racing, about 250 dollars, not sure of the part number, but they will not be hard to find.

I feel inclined to tell you, that although these bars have worked flawless for me, a lot of people have had problems with them breaking, I do not know if it has to do with installation, or exactly why they break them on a street car while my 11 second car runs them for years, but you may want a second opinion before you go out and buy them.

I am not trying to steer you away, as I said I have had great results, but I would feel terrible if you followed my advice and got them, only to have them break. Maybe someone with firsthand experience breaking them can chime in on the failure.

 

do you have any pics of your setup im not exactly sure as how these bars work because i have only had leaf spring vehicles before

 

what locker would you recommend if i cant find one with posi

 

Yes the rear cover gasket is the one i was talking about, sory if I wasnt clear.

What happened was the entire final gen B body run was built with the wrong diff cover gasket insatlled. The cover has a trough stamped into it that directs oil slung around by the ring gear to two holes at the 9 o,clock and 3 o,clock position that bypass the inner diff bearings and feed lube to the outer axle bearings.

The gasket used didnt have the two holes so the outer bearings didnt get the right amount of oil and would eventualy fail. Usualy a few thousand miles after the warranty expired.

People not aware of this issue would rebuild the rearend at significant expense then re-instal the very same gasket! After all it's what GM said to do lol.




Since you would be replacing the stock TQ arm most likely and you would be doing some fab work allready I'd just fab a new arm.

I would mount it to a fabricated cover like the GNX cast cover.

https://secure.mysuperpageshosting.c...ce.com/gnx.htm

Supposedly having the arm on the passenger side compensates for engine torque and helps the buick launce straight.

 

im gonna go with the lakewood bars instead of the torque arm i think. they look cool underneath and i plan on taking it to the strip a lot so the added traction would be helpful

 

When I installed my second gen 8.5, it was easy, due to my using lakewood lift bars and not needing a tourqe arm, but you will find a lot of negative opinions on these bars on this forum. I have used them for five years with great results and no problems, but not everyone has been so lucky.

Here is the link to my post on my 8.5 install.
https://www.thirdgen.org/forums/fabr...5-10-bolt.html[/quote]


i dont really understand how you deleted the torque arm. ive talked this over with a few other people and they said that you cant delete a torque arm because it holds the axle in place. i would like to do this setup on my car i just need to make sure that this will get rid of the torque arm before i go buying this stuff. also does this look like the kit you used?

http://store.summitracing.com/partde...5&autoview=sku

 

Yes, that is the kit I have, and it does replace the tourqe arm, I wonder if using the two together caused some of the failures I have heard of.

These bars work in the same fashion as a ladder bar, but because of there short length, create a lot of antisquat. They do carry some of the drawbacks of ladder bars as well, most notably, binding. Because of the design of a ladder bar, the axle is not allowed to articulate. This is great for the drag strip and a straight launch, but when tranversing uneven pavement, the weight of the car will force the axle to articulate, and the bars will have to twist. This however is not a huge deal, I have driven my car everywhere and never notice the binding. Also, a lot of serious street strip cars use ladder bars on the street with no adverse effects.

 

thanks looks like the 8.5 it is then behind a 2004r performance build

 

I would get the Truetrac for the 8.5 ten bolt as well. Less the 500 bucks.

 

i got one out of a 77 camaro with posi and what looks like 3.42 gears for 45 bucks plus tax with brakes even though i will be converting it to disks

 

Good deal, you are well on your way to having a durable rearend without breaking the bank!

Disc brakes are great and all,especially for a pro touring car with big heavy wheels. But for a footbrake drag car drum brakes are really better, and with all the brakes in good shape and adjusted properly, these cars can stop very well. I have seen many people "upgrade" to discs without actually gaining any stopping power. In order to really reap the benifits you need to change you proportioning valve, and I believe the master cylinder.