I have a local guy who wants to sell me a 94 4th gen 10 bolt rear. It has 3.73 gears, an Eaton posi unit, heavy duty axles, and fresh bearings. It obviously has disk breaks. It soposedly has practically no miles on it since the rebuild. It is actually in a thirdgen with a blown motor now. According to the seller, he bought it off a guy who rebuilt the whole car to eventually run it low on oil and then boom! He says he wants $800 for the rear and will throw in the performance parts in the rear such as the adjustable pan head bar and maybe the shocks.

Is this set up stout? Will it last behing my 350-400 rwhp with non-sticky tires? Is it worth the cash? I'm thinking yes.... Any opinions appreciated

P.s. I have craigar wheels on my car now and want to reuse them after the swap. They will work on this rear right? I'm aware this might require some grinding on the calipers.

 

No way. Unless you have it looked through and see receipts of date of rebuild. You can have your rear rebuilt for that amount.

 

dont you have to narrow these for a third gen also?

 

Really? what do you think I should offer him then? I am going to meet him and actually see it this week.

 

Be sure that it has the Eaton Posi before you do anything. If it still has the Auburn then run away from it.

 

No I am pretty sure they just stick out a little bit past the thirdgen body (maybe 1 inch each side)

 

I definitely want to pull the diff cover to see if it is indeed what he says it is. Again what would you price something like this?

 

This is what hes telling you has been done and approximate price.
Unfortunately you have to take his word for most of it unless he can show you receipts.You will have to ether count the teeth or look for a stamp on the ring then be able to identify the Eaton.

1. 3.73 ring and pinion =$ 200.00
2. master bearing kit = $ 90.00
3. axle bearings and seals = $ 30.00
4. 28 spline Eaton posi. Unit = $ 500.00
5. 28 spline axles = $ 250.00
6. installation/labor = $ 300.00
7. Total of $1,370.00

Here is the Eaton =

 

Yeah it sticks out but not much to notice IMHO.

I would look at it, have him open the cover and make sure there are no metal flakes. Really put your finger in the bottom of the oil and check. The thing is you could have anything from a bent axle(happened to me) to a one wheel wonder. It's hard because you can't test drive it.

If I was you I would have a mechanic come with me or a buddy that knows reef ends and have him look it over. If he says its good then I wouldn't go a penny more than $500 and that's with receipts or like Big Gear Head said make sure what's inside it. Take the cover off, if the seller gives you a hard time tell him you'll give him $20 either way for fluid. That's what I would do personally because ive been. Burned

 

No body,I mean no body that is selling a rear axle assembly should be surprised when you ask him to pull the cover especially when there claiming there is a Eaton inside. If any thing bring a oil pan/catcher to put under it so that eliminates him having to deal with it.Bring a flash light also.

 

Yes^

 

@ronusmc thanks for the picture and the prices. The thing that sucks is that he probably doesn't have any proof of purchase(s) because he bought it from someone else. According to him he has a large collelection of thirdgens. He soposedly is one of the most sought after guy for parts in the north east (his name is Tom he's from CT). I guess he's a member on here but he said he doesn't visit much.

@neeb_usmc with all of this in mind I think $500 sounds fair. I guess I was a little gullible thinking everyone is always 100% and not trying to burn anyone lol.

I like the idea of bringing fluid and a drain pan. I'm going to try to get my friend/awesome mechanic to go up with me. Either way like you mentioned, its tough to identify all of the parts anyways. If the oil is clean, everything looks as it should and he throws in some new rear suspension components he will get 5 hundred from me. Ill start at 4 after bringing all these things up ; )

Anything else I should look for?

Oh btw guys thanks for serving !

 

Hey I served for y'all, you supporting us is all that matters. So, tell your mechanic friend you'll buy him a beer or 'soda' if he comes with. If your going to offer $400, let your buddy hold $100 and if all is good tell the guy all you brought is $400. If he doesn't budge tell him thanks and start to walk away. I bet he sells it for $400, if not ask your buddy if he has any money and bump it up to $500. I personally wouldn't go higher. Axles could be bent and there's $300 alone for cheap ones. Ask him how much hp the motor had

 

If the rear end is not in a car you can set it up on jack stands and turn the pinion down before you remove the cover. That way the oil stays in the rear end and you can still look at everything. If you have a dial indicator and some gear marking compound you can check the backlash and the contact pattern too. Check the axle end play. Many times that is a good indicatin of how much wear is on the clutches. If axle end play is excessive then the clutches are probably worn out. If the axles only move about .005 to .020 inch then they should be very good.

 

Ill see if I can get my guy to go with me. I talked to him today and he told me the same things you guys did. Check the oil, the play in the axle, etc.

Trouble is it still is in the car. Maybe ill try and talk him down and offer me uninstalling it for him. I don't mind. I sort of rather it that way.

Ill see what he says about how much power the motor pushed out

 

Going to look at the rear in 30 minutes guys wish me luck haha

 

Damn that guy was stubborn as a very stubborn mule. He was a nice guy but was not being lowered. Well he literally had a 3rd gen heaven going on there... at least 8 visible cars. He was not budging on the price. The oil was like brand new. No traces of metal. No pitted gears. Very new looking hardware. Slight axle play. All the work was done by a local shop with a good rep. Good breaks. Included components of rear. I really tried getting him down but he was not having it. I made him throw in all of the interior parts I needed and he agreed. I really couldn't walk away from this since I have been looking for about 1/2 of a year for this very exact setup so I bit the bullet and bought it for $800.

Thanks on telling me what to look for guys.

 

That's an Auburn. I would have said no thanks and ran away, fast.

 

Wait ... That's not an Eaton. I only left a deposit. Is that what the sprocket difference is?

 

Nope, not an Eaton. That's an Auburn. Look at the picture that ronusmc posted above. That's an Eaton.

 

So get my money back...
Fast?

 

My opinion on the Auburn is from personal experience. I've replaced several of them in customer's cars and I've seen what a pile of crap they are. Not everyone has the same experience with them, but I would not pay $800 for a rear end with a Auburn in it. If it had the Eaton Posi then $800 might be acceptable.

 

I see the difference now in the middle of the unit where the springs are. Damn. I brought that picture and it looked like it. Its tough identifying something you no nothing about.

I do know the rep of Auburn differentials and do not want one in my rear. That's why I was looking for one with an Eaton... I will get my money back and start looking again I guess...

 

Don't feel bad bro! I got shafted on a supposedly good 9 bolt posi rear with disc brakes a few years ago. I had to replace everything except the axles. My total investment was around $1,800 when all was said and done.

I should have invested in a custom Ford 9 inch made for 3rd Gen Camaro's.

 

Wow that sucks. Yeah well I only left a $100 dep and have a "handwritten" receipt. Like I said he seemed like a decent character so I hopefully wont have an issue getting my deposit back... I better not lol

 

You probably can find a Eaton cheaper than $500.00 along with some of the rest so if you don't count labor that means your only $200.00 away from "brand new" parts. Here's a link to my build = https://www.thirdgen.org/forums/tr...de-photos.html (10 Bolt upgrade photos)

 

I read the article... Good info

I'm going to look into building one. I wish I could rebuild mine except mine is 26spined one...

 

My original diff on my 85 Z was a 10 bolt 3:23 open carrier with 26 spline axles. It lasted a very long time and the only reason I replaced it was because a couple of teeth on the ring gear broke off. (I think my son did a netural drop) I've had good service with a 10 bolt in several cars and for many years.

 

You can get 28 spline axles for yours. Just get axles for a '90 to '92 and use them. Get a 28 spline Eaton Posi or Yukon Dura Grip and go for it.

 

 

The way my axle search is going, it looks like i'm going to have to go down this route. Thanks for all the info guys...

How do you guys like torsen diffs?

 

They are fine. Better for auto cross and road racing than a clutch type differential, but probably not quite as good as a clutch type for drag racing.

 

I know I can get the 28 splined axels in my rear but I would be restricted the carrier 2 gear ratios because I have 3:08's right?

Do you think I'm better off going with a $250 95 Camaro rear and running it till the auburn gives up? Then I would put a nice eaton in there. I would have a posi 3:42 that way and go from drums to disks.
The rear has the pbr calipers on there btw

 

The rear end housing will take any gear that is available. The only thing that you have to change is the differential, which is what you are going to do anyway. Just get a 3 series Eaton Posi or Torsen, 28 spline axles and a good installation kit and put in whatever gear you want.

If you can live with the wider rear end then you could use that '95 rear end. The Auburn might last a long time and it might last a week. You never know. It also depend on how you drive it. If you do a lot of burnouts it's not going to last long.

 

Oh I get it now the housings are all the same. It's just the actual differentials that are the numerical carriers.
It depends on what this rear looks like. I really want disk breaks in the rear. Do you think the breaks make this decision?

 

You can transfer the brakes to the rear end that you have now. There is information on here about how to do this.

 

Keep in mind that switching to rear disks requires a J65 type prop valve and 83 Camaro brake line fittings are a different size at the master cylinder. I went through a lot of trouble, time and expense to convert mine and would not do it again. I do think rear disc's look good, but drums keep the rims cleaner and the E brake works better in my opinion. Check with Ed Miller of www.flynbye.com on a disc kit for your 10 bolt.

 

I was under the impression that the front breaks are the primary and the rear are used to keep the rear from sliding left or right while breaking or something to that effect any way.Drums accomplish that just fine.

 

http://westky.craigslist.org/pts/3678462378.html
I spotted this in Owensboro Ky. Thought you might be interested. I don't know if that's a good price or not. It doesn't say if it's a 2 or 3 series, but it looks like a 2 series to me.

 

I honestly thought disks were a major upgrade. I guess I was under the impression that disks were all mighty lol.
I was seriously researching (you guys made this very easy) putting together a rear myself from my housing. I was planning in purchasing everything to do this after my motor is in (which the progress of the swap is documented in the build thread in my sig if you guys want to take a look : )).

However I have had a Wanted ad up on cragslist for a while now. I got a call today. I think its a winner

'92 10 bolt (obv correct width for my car)
drum breaks
Torsen Unit
3:73
Reinforced Cover
fewish miles on it (said 800-100)

I made sure I started off the negotiations at the right price and even shared of my experience last time

Price $400

No receipts. Going to throw in 3:42s from a 4th gen project. Hes parting out the car. He also has a lot of performance rear suspension parts that I can grab too.

So does this sound right guys?

 

I contacted the guy. He doesn't know what carrier it is. I'm going to see if he would be willing to ship it. Thanks a lot for the good looks!