Hi All!

Around two weeks ago I got my new gear set and complete posi for my GTA. Got the 3.45 gear set, but now since I thought this were a job for a real mechanic i removed my rear and left it with the new parts at his shop. Now after ~2 weeks there still is porblems installing this.. Now finally he said that the new pinion is longer then the 3.27 one.. And it for sure is, no question about that.. ~3 mm.. Should it be this way? Should this really be a problem, I think there now is to much play between the bearings as he explained it to me.. So now I asked him just to reinstall the old parts.. This will be the most expensive change of axle bearings I guess ever done... :/
The new pinion and gear are from 9-bolt so I am sure it actually should fit in this rear.. but(!) why is there still a problem with to much play? I read about the crush sleeve - is it possible that the machanic used the wrong crush sleeve? Should an other dimension pf crush sleeve be fitted when a new gear set is used?
Hope someone can understand my problem here.... :/

KR, Richi///

 

Who did you order the gears thru? Call them and match the codes on the box they sent you and ask questions.... Or call whomever you bought them from and raise some Hell if the mechanic is right and they won't work! Good luck...

 

Your first problem was taking this rear end to a shop. 9/10 they dont even know what the hell is under your car, and since the 9 bolt is so unique unless people know their way around them they are bound to mess something up. As for play in the rear end, usually play in a 9 bolt is solved by shimming the rear end, the same way a slipping 9 bolt is tightened up.

 

If I understand you the problem that you are having is with too much space between the pinion bearings. Did the mechanic crush the spacer or did he just tighten the pinion nut until it stoped turning? It takes around 300 foot pounds of torque to start crushing the spacer, and many times people just don't try hard enough. I've had many people ask about this and they just don't understand at first that it takes so much torque on the nut to crush this spacer.

 

Hi All!

First - Many thanx for fast answers...

Now trying my best to answer some questions above also..
-Bought it from Glenn at 9-bolt so I guess it should be the correct gearset to the GTA....
-Problem is as stated (and as I were told) too much space between the pinion bearings... He said he tightened the nut as much as just possible and still there were too much space left.. :/ I think the mechanic have worked here in Sweden with american cars from mid 80 so I hope(?) he knows what he is doing?.. Still is it much more torque used on the 9-bolt pinion nut than on eg. a more usual 10-bolt rear?

Do any anyone that have changed the gearset on a GTA or Iroc Z28 remember if there were any differens in the length of the pinions? This so a different crush sleeve or perhaps even a solid spacer should be used instead because of this?

Do know what to do now, else than having him to put the old gearset in place.. :/

KR, Richi///

 

When doing the trial assemblies you should leave the spacer out. You only put the spacer in on the final assembly. Try installing the pinion without the spacer and see if it will work. Then get the pinion depth and backlash set so that the contact pattern is correct. Then it is time for the final assembly and you can install the crush spacer.

 

Another issue to consider is the rear (next to the gear) pinion bearing. There are two. No one I spoke with shows the smaller one in catalogs, but I have it in my car. If you housing requires the smaller bearing, and a "standard" bearing kit is ordered, the pinion with stick out about the 3 mm you described. Fortunatly for me I still had my old bearing and was able to match it up. But no one, even the place I ordered my gears from showed the smaller bearing.

Now if for some reason you had the reverse problem, small bearing in the large housing, you'd have the play between the bearings you described. Seems like a "professional shop" should be able to figure that one out though...

I also noticed a problem when setting up my 9 bolt. It takes an INSANE amount of torque to crush the crush sleeve. I mean with the pinion yoke firmly held with a proper fixture and a 4' cheeter bar I still could not get all the play out of the pinion bearings. An issue that made it worse was the "soft" washer provided with my bearing kit. I simply could not get it tight enough because the soft washer deformed into the yoke's splines and around the nut. Effectively locking the two together. What I had to do was purchase two hardened steel washers, use the factory flanged nut with a liberal amount of bearing grease on the washers, nut and threads and it still required a 4' cheeter bar to finally get the sleeve crushed. I then removed the hardened washers, cleaned the threads and nut with solvent and reinstalled the nut with Loc-tite to the proper bearing preload.

 

Hi!

Thanx for all answers. Yes, I also got a smaller pinion bearing attached to the pinion. This of course did not fit to the cap I had.. And made the matter even worse. We also did not found any info about this smaller bearing.. :/ This is strange..:/
Anyhow changed the bearing to the "original" larger one, but still too much space.. :/ The pinion shaft on the newer pinion (for the 3.45 gearset) is actually ~3mm longer... But(!) now finally this were solved by turning of the crush sleeve ~1.5 mm on each side and woops it the pinion fitted in its place just perfect! :P :P *phew*

Now the axle is in my garage and I just finished painting it all black.. Hopefully putting it in place tomorrow.. :P :P

 

You aren't suppose to turn the spacer. It's suppose to be crushed. I guess he wasn't putting enough torque on the nut. Hope it works out for you.

 

:P I meant cutting of ~1.5 mm on each side of the crusher sleeve in a lathe... My knowledge in English words seems not so gooooooood these days.... :/

KR, Richi///

 

Do not turn down the crush sleeve in a lathe. Most of these aftermarket sleeves, no matter what rear end, are much harder to crush than the original ones. A trick is to just get it to start crushing in a hydraulic press. Do it carefully. After that you can easily crush it further, to get it started is what takes a good amount of force.

You can also check the old crushed one that came out, have a machinist (or if you're a machinist DIY) turn a solid spacer a bit shorter than the crushed one and use shims to shim up the solid spacer and set pinion bearing preload that way.

 

Yea, I knew what you meant by turning it. You shouldn't do that. It is suppose to be crushed.