Differential

Here is the update from the tranny shop today.

If you have read some of my Transmission thread then you'll know what I'm talking about.
http://www.automotiveforums.com/vbulletin/showthread.php?t=321280

Okay, so its the rear end thats giving me the problems.
WHOO HOO!! Another part to replace! Man, been like 7 different issues in the past 2-3 months! :swear:

So, if they are telling me that the rearend is 'whining' down and it could be the gears or seals or whatever in the back, what would I need to replace?
Again, I don't know much about the rearend in the Trans Am, nor the transmission. I'm just knowledgable with the engine work. But I do know that higher the gear, the more torque I guess?

So anyway, how and in what way would be a good aftermarket replace part for the rearend? I can't afford the 12 bolt system I keep reading about. If it costs 2K then its just a little much right now.
If I replace the gears (which actually looked fine when I got the fluid changed a couple of months ago) will that solve the rearend 'whining' and knocking problem?
If I go with a whole new kit for the rearend, will it solve the problem, and for how long? Also, if I'm going to replace these parts, what gears should I invest in? Heck, I don't even know what my stock ones are.

I need to post a signature, remember, my car is a 96 Trans Am without any mods. Besides new parts...*sniff*...I think I'm going to cry.

I've seen some differential rebuild kits on eBay...should I look into those? What size and specs does my car have?

Do you plan to do all the work yourself or do you have a helper that has done this before?.

Also There really isn't much is the rear end to break besides the ring gear teeth or bearing's. So I would bet that you could change the fluid, Add one bottle of posi additive and the noise would go away but if you have a helper I would serouisly recommend some new gears and what is your car Auto or stick? and do you know where your RPO sheet is?(glove box or Driver door).
John

Well, I don't think the teeth are broken. There is no way it could have. The fluid was just changed not more than 4 months ago. And I looked at the gears to make sure they weren't broken.
I also had it re-sealed because it was leaking out of the U joint and the gasket of the differential cover.

If its the bearings, would that make the "whirring" sound when I'm driving and slowing down? Would it also make that clunking noise back there?

Oh, its an Automatic too. And the sheet is on the door of the car. Is that where I can find the specs to it?

No, I won't be having a helper do it. I could take it to a shop where a friend works on a Saturday and get help from some mechanics...or I was just thinking of getting it done by someone else.

Oh, and to add on to the list of problems. A friend of mine backed into my car last night and screwed it all up! Well, not to bad but backed into the right rear panel and bent in the metal gas cap shield and put some nice scratchs all down the side. Good thing I know a guy that can do body work too. *sigh*

Did you change the rear diff. fluid yourself? If so, did you put the limited slip additive in with the gear oil or just gear oil? If you didn't put the additive, the discs used for the limited slip differential will stick and make noises (clunk perhaps). Also, if it is "whining" that is probaby bearings...either carrier or pinion depending on whether it is constant or just under load. Your local mechanic would be able to tell you by listening or riding with you. When my '94 T/A had a rear end whine, I needed carrier bearings and I couldn't afford to do the whole job of replacing all the rear end bearings...so I had the carrier bearings replaced only and it cost about $700. Never gave me another problem.
If you do it yourself, just keep in mind theres a lot involved in differential work that involves a certain knowhow. You need a press and it would be a whole lot easier if you had a car lift. Just have a printout of the specs of your rear diff. and the step by step process of what to do unless you have a friend who knows how to do it.
Before you do anything though, make sure you put that additive in there. If you can't remember, just dump the fluid and put new in plus the additive just to be safe. That should cost like $30 and could quite possibly fix this problem.

Its a constant "whining" sound back there.

No, I didn't add the fluid myself, I had shop guys do it one day when I was thinking about it, when they were doing the Opti. They added the slip additive. Do you have to add the whole bottle of it? Hmmm...
I don't think adding, or changing the fluid, is going to solve this problem. This noise has actually been there for awhile...its got to be something else. Maybe bearings like your saying.

Bearings were $700 just for the carrier? I don't know what your talking about and I don't know where they are but dang! Thats a lot of cash! I just paid 500 for this thing this month because one of my injectors were bad and its my daily driver. Geez... :banghead:

What if I get this kit? Does it include all the bearings?
I don't think I can do this job myself. I don't have the tools for it. Crap this sucks.

http://www.schochperformance.com/details.php?partnumber=SLP-64047&PHPSESSID=866a39e42052c462412ee2e49501a25b

Should I just upgrade to 3.73 while doing this too?

http://www.schochperformance.com/details.php?partnumber=SLP-64046&PHPSESSID=866a39e42052c462412ee2e49501a25b

Do you think its the differential at all? Those are expensive...I think I'm going to cry.

Well, I don't think the teeth are broken. There is no way it could have. The fluid was just changed not more than 4 months ago. And I looked at the gears to make sure they weren't broken.
I also had it re-sealed because it was leaking out of the U joint and the gasket of the differential cover.

If its the bearings, would that make the "whirring" sound when I'm driving and slowing down? Would it also make that clunking noise back there?

Oh, its an Automatic too. And the sheet is on the door of the car. Is that where I can find the specs to it?

No, I won't be having a helper do it. I could take it to a shop where a friend works on a Saturday and get help from some mechanics...or I was just thinking of getting it done by someone else.

Oh, and to add on to the list of problems. A friend of mine backed into my car last night and screwed it all up! Well, not to bad but backed into the right rear panel and bent in the metal gas cap shield and put some nice scratchs all down the side. Good thing I know a guy that can do body work too. *sigh*The probelm is that whoever changed your pinion seal tighten the pinion nut with a impact wrench or just over tightened it without checking preload and thats whats causing your whine but do gears anyway with a mechanics help, You will be real happy with the outcome I recommend 3.73's. Also use a breaker bar and a torque wrench to adjust the pinion nut next time. Good Luck.
John

Its a constant "whining" sound back there.

No, I didn't add the fluid myself, I had shop guys do it one day when I was thinking about it, when they were doing the Opti. They added the slip additive. Do you have to add the whole bottle of it? Hmmm...
I don't think adding, or changing the fluid, is going to solve this problem. This noise has actually been there for awhile...its got to be something else. Maybe bearings like your saying.

Bearings were $700 just for the carrier? I don't know what your talking about and I don't know where they are but dang! Thats a lot of cash! I just paid 500 for this thing this month because one of my injectors were bad and its my daily driver. Geez... :banghead:

What if I get this kit? Does it include all the bearings?
I don't think I can do this job myself. I don't have the tools for it. Crap this sucks.

http://www.schochperformance.com/details.php?partnumber=SLP-64047&PHPSESSID=866a39e42052c462412ee2e49501a25b

Should I just upgrade to 3.73 while doing this too?

http://www.schochperformance.com/details.php?partnumber=SLP-64046&PHPSESSID=866a39e42052c462412ee2e49501a25b

Do you think its the differential at all? Those are expensive...I think I'm going to cry.I would upgrade to a new carrier before buying $700 bearings thats a rip off. I doubt its the bearing's but it could be the bearings/clutch pack but I would put money on it that a impact wrech was used to put your pinion nut on and you can never get the proper 10-15 pounds on preload with a impact wrench almost every shop misadjusted this part and it would most certainly cause whining and would also change your backlash but yeah 3.73's are the way to go.
John

So should I just go ahead and get the install kit? And just do it all?
I found this site...not too bad on the money...what do you guys think?

http://www.fasttoys.net/9398fbodyframes.html

(edit)
Oops, I checked the link and it doesn't send you where I want...just go to the link I gave and in the left side click on Drivetrain and they have kits and pinion and stuff there.

Are those parts worth buying? I know you get what you pay for...but...

So, can anyone tell me if the Motive Gear parts are good? Or should I buy SLP?
Motive Gear link, click link then go to Drivetrain link on the left side and scroll down to see gear and installation kit.
http://www.fasttoys.net/9398fbodyframes.html

Also...what does "For 3 Series Carrier" mean for the 3.73 gear?

The bearings weren't $700, the labor to put them in was. I don't have the tools to do the job so i had to pay the dealer to do it.

So should I just go ahead and get the install kit? And just do it all?
I found this site...not too bad on the money...what do you guys think?

http://www.fasttoys.net/9398fbodyframes.html

(edit)
Oops, I checked the link and it doesn't send you where I want...just go to the link I gave and in the left side click on Drivetrain and they have kits and pinion and stuff there.

Are those parts worth buying? I know you get what you pay for...but...
3.73, 3.42, etc. 3 series ratio numbers...

OK I quoted the wrong thing, but you get what i was saying right?

Ya, I get what your saying. :iceslolan

I've realized in this forum, you can't really screw up with what you say...we are all on the same wave length...well...pretty much. I think...
:jump3:

Well, I guess I'm going to take it to a shop, have them diagnose the issue and find out if it needs bearings or what. I just hope I don't need a new differential...is it possible?

Man, so many questions huh?

I order my install kit from these guys and it was pretty complete http://nationaldrivetrain.com/shopsite_sc/store/html/page4.html
And I doubt highly its your bearings, but it could be. I would loosen the pinion nut and tighten it back up with a breaker bar and Torque wrench to 12 Lbs and see if the noise goes away before you start searching for rebuild kit or replacement.

I agree there. Diagnose what problem you have and see whats involved in fixing it before just replacing the whole setup. I just always take stuff like that to the dealer because they repair/rebuild differentials all day long and I have built one...I trust them to tell me whats going on more than I trust myself on stuff like that is all. Good luck and hopefully its not an expensive fix.

ps. If the pinion bearing was overtightened, then he'd have to replace the crush sleeve in there. He can't just loosen it and retighten it to the proper torque. I have just found that its easier and ultimately less stressfull to take stuff like that to a certified mechanic rather than mess with it myself unless I know what im doing. Otherwise I always end up doing the job like 3 times before I get it right and it would have been better to just get it done right the first time.

A crush collar isn't useless right after tightening it. I'm sure since it was just installed he will be fine but if you feel you need another on this will require removing the differential and reinstaling and checking backlash and preload all over again. I say just disconnect the driveshaft remvoing the pinion nut, remove the yoke and reinstall the yoke and pinion nut to 12lbs then reattach the driveshaft and take it for a ride. I bet it would stop.

does it clunk at slow speeds when in reverse or making slow turns? mine did that and it was the spider gears.

Not so normally in turns. I think once it did...but that was when I was slowing down to a stop.

Usually its when the trans is shifting from 1st to 2nd then 2nd to 1st, it'll clunk. And the "whirring" sound is constant whenever I'm accelerating or decelerating.

Sucks...its really annoying...feels like it'll just die one day.

rebuilding the rear axle (in my opinion) would be your best bet.Not only can a bad rear axle cause your transmission to prematurely fail,but it can also ruin warrenties,on transmission rebuilds.Any customer that comes to my shop,gets the 30/30 warrenty,if they have a bad/severly worn/noisy rear axle.And most places check that sort of thing,before they start paperwork on warrenties,or service.

Of course it looks like they didn't check mine.

Great...so that means I can't wait till after Christmas to get this done...looks like I need to order parts now.

No 3.73's are a all around good gear for a Auto LS1 F-body and you will need to program for the new gears and what better time to tune the PCM as well.

Hmm...lets say I upgrade to 3.73's or 3.42 (I think thats what the LS1 stock has). Would I need to get reprogrammed? Currently I think my car has the stock gears of the 96 Trans. GU2 I think it lists under the RPO sheet. Too lazy to look it up.

I was thinking about doing the stock LS1 gear because I plan on still using it for HWY miles and such. Daily driver you know?

How long is a "whirring" rear end going to last?

Stock manuals use 3.42's but Auto could have come with either 2.73's or 3.23's optional. I think 3.73's would be ideal for great performance while still not killing MPG or top end or you could go for 3.42's if its a Auto.

Sorry, just one more question about this...this thing is a huge deal to me.

If I was to go 3.42 with my automatic...would I need to get a new differential that is a 3 series or a 2 series? I guess the 3 series has more bolts on the differential?

If I need to get a 3 series...which company would be better?

Yes you need a 3 series Differential if you switch to any gear ratio from 3.23's up and I use a AUburn locker but for your needs I think a Torsen would work just fine, You can find one from www.car-parts.com (http://www.car-parts.com) and search under ring and pinion only for some reason they are listed under there and no the bolt;s are no different the only difference is that the pinion size is diffenrent and the ring gear is different and the spacing were the ring gear is placed in relation to the pinion gear is different.

You were talking about an Auburn...look at this! Would this work in a 96?

http://www.lmperformance.com/3767/2.html

Its priced at $284.95. Does it just not have posi traction or something?

It has Posi...based on the picture.