1SlowFormula

Hey all I just got around to putting my spare 10 bolt in that was set up with 3.73 gears.

I came into a few issues though, but nothing too major.

1. Broke the swaybar endlinks, 11yr old rust sucks, got to pick up new ones today...
   
2. When lowering the old rear it fell off the jack, one side landed back on the jackstand stand the other grabed hold of and was suspended by the brake lines that I had bungy corded up, it was only on the rubber section of the brakeline and there appears to be no leaking or issues from the line...
   
3. When swapping units I realized the spare axles didn't have the 4ch reluctor rings, but no biggy since I will be pulling ABS later and TCS is already gone, so I pulled the sensors from the backing plates and the rear section of the wire harness for the ABS/TCS sensors...
   
4. After getting it all in, I am not sure if it took enough fluid. I put in the gm limited slip additive and 2 qts of gear lube, ran the rear around in drive and reverese a few rotations while on the jackstands thinking it would get the fluid to areas that it wouldn't just seep to and when checked everything and it didn't need any more. Was this the correct method and ammount of fluid? More came out of the old one with the stock cover, but this one has a support cover and a little less room behind the cover so I am not sure if that is the whole reason for less fluid.
   
5. I took it for a test drive and the rear sounded good, but the brakes were squelling/grinding whenever I didn't press on them, I hope it is just dirty rotors, everything was filthy when I finally got finshed so they were dirty/oily, and not an problem from dropping the rear on the brakeline...

What are your thoughts?

BTW, my A4 w/3.73 gears rocks now, my test run on the highway last night, 55 - 90 came quickly compared to the 2.73's...

Capn Pete

1) Rusty end-links, oh well!
2) Just keep an eye on that part of the brake line in future ... make sure it doesn't start leaking there ... it should be ok.
3) I guess you solved your own problem .
4) Just shy of 2 full qts is correct AFAIK . That's all I've ever (been able to) put in. I think you're fine .
5) Maybe your calipers are getting a little "sticky" (sliders) and because of having them off and the piston compressed, maybe they have to find their happy "middle" ground or something? ... I'm sure they'll find their home again and quiet down .

Yeah, you should enjoy the improved acceleration ... stop-light to stop-light becomes really fun! The only thing you'll miss is a little bit of highway mileage, and you spend a lot less time in 1st gear!

1SlowFormula

no kidding about first gear, I was crusing at light throttle and it was shifting out of first around 5 MPH or so, and it was really like it was never there... I can't wait to get the new endlinks and install the swaybar and take it out and play, I might even bring it to work this week if the weather cooperates...

1SlowFormula

OK I drove the car in to work today, and there are still a few issues but again nothing serious.

When I reprogrammed the computer for the gear swap I scaled the TCC lockup down with the shift points and all, but they will probably need to be raised a little since I kinda like the ability to let off when passing cops and not having it hold the gear and do that decel exhaust crackle/pop our cars do...

As for the brakes they are starting to **** me off, they are still grinding/swooshing with the road speed and now it doesn't stop when you apply the brakes it just gets a little less noticable, I drove it 12 miles today and about 3 of those were high speed highway miles and the rest were stoplight to stoplight secondary roads, you would have thought that they would have seated themselves by now...

And the third issue, is now I am getting the d-shaft vibe that I have read soo much about and having the 2.73's it was never there before, but now the d-shaft has to spin much faster then before per tire rotation. I guess I will try clocking it and if that doesn't help I guess either balancing it or going for an aftermarket shaft...

I guess all has gone well considering the scale of this swap, but I just wanted to share my ezperiance with other who think it might go smootly...

Capn Pete

Here's a question ... you said you put a "spare diff" in the car, right? What year did it come out of??? (more specifically, was it from an LS1?? ). I'm pretty sure I read that LS1 axles are about ~1/8" or so longer than LT1 axles . That would offset the rotors just enough to cause them to rub at all times.

As for the driveshaft vibes, heh heh, yeah ..... try putting in a poly trans mount ... you'll go crazy!! (it'll make it even worse!) Try getting the DS balanced, or just learn to live with it?

1SlowFormula

Actually not sure what year is was from I should look up the post where I bought got it from a member on here, I know it was a 4 ch rear with 2.73's it could easily be an LS1 car... But after taking it for a spin at lunch I think your right though, since it does it all the time and is worse on turns when the little slack pulls it out more. If that's the case then no biggy, I can figure something out there, maybe I will try spacing out the backing plates or something. Thanks for bringing that up, it's something to look into now...

Oh and I do have the poly mounts actually all my mounts are poly, so this vibe is really going to be a pain if I drive the car on the street too often...

1SlowFormula

The guy I got it from has a 97 Z so that would make it an LT1 car. So there goes that idea, maybe though I can still look into any slight differences since I used my car backing plates on the other rear and there could be slight variances, right?

Hold on, I painted the rear but it wasn't thick (~3-4 coats of rustoleum hammered metal spaypaint), but do you think it might have spaced the backing plates out enough to let the rotor scrape the caliper a little?

nodnarb481

boy that sounded like an installation process I would go through... haha dropping **** and breaking ****

Capn Pete

Yeah, I couldn't live with the vibrations anymore so I put back the factory LS1 tranny mount. But I've never taken my driveshaft in to be balanced, so I might consider that over the winter?

1SlowFormula

NOT IF YOU CAME DOWN TO HELP...

Just kidding, but seriously I wouldn't try to swap a rear alone again it was too much of a pain to keep it supported while attempting to use the jack too...

nodnarb481

hey man I would love to come down to help.. im not much help ill admit that..but i know a thing or two about having extra hands since my 2 hour panhard rod install. plus i just like being around that ****.. didnt realize you were from philly..

Capn Pete

Hmmmm . How about the parking brake ... when you had the calipers and stuff off, do you think you could have (somehow) affected the parking brakes / adjustment?? I'm just trying to think of possibilities now for brakes dragging.

I wouldn't think that a coat of paint would space out the backing plates that much though?? (although you never know!! )

I'm no brake expert, but I still wonder if maybe you've got a sticky caliper?

1SlowFormula

Thanks agian for all the help, it gives me things to look for, but unfortunatly I tweaked my back (yes, I know, I am getting old) and am not moving far from my office chair today to look into it for a few days...

1SlowFormula

OK, finally got it figured out and I have no idea WTF is up with my luck when I do a project like this...

I took the tires off and found this... On both sides

Just a little contact.


That was gringing some.


OK, maybe grinding a lot.


So in trying to figure out why they were grinding I found that from the end of the tube to the face of the axle flange there was a difference of ~1/4 (somewhere between 3/16" and 1/4", like about 7/32" or so) between the old setup and the new one. My old axle flange was out further then this one, making this one pull the rotor into the backside of the caliper when I tightened down the lugs nuts.

The fix was easy though since I had some sheet alum. handy and made shims to space the rotor out from the flange ~.1", I thought about going bigger with the shims but this gave plenty of clearance. Now the grinding is gone...

Now, I just have to wait for the tracks to open in a few months, since today was the last open day this year, to see how she does with the 3.73's...