JEB99TA

iTrader: (32)

Here's what I have ... Strange 12-bolt with 3:73 gears (A4). Rear axle seal was replaced about 6 months ago and the car only has 58,000 miles on it. I do have an adjustable torque arm. The drivesahft is tight with no play whatsoever.

I'm getting a high-pitch whine like a jetliner slowing down when coming in for a landing. This is on deceleration ... no other noises until I slow down to about 10 mph and turn slightly right or slightly left (turning the wheels left or right sharp produces no noise and the rearend sounds normal) ... sounds like a combination of tires rubbing and metal grinding. It's not coming from anywhere but the rearend. T he tires all have good clearance and the neoprene bushings in my LCA's and P/H Bar have been pumped full of grease wheel bearings were checked by the dealership.

To verify, I took it down to the dealership and they said the rearend setup was wrong. This didn't start until I took it to a shop to get the pinion seal replaced. It's gotten worse over the past few weeks, so, gonna' have to get it in the shop.

Any ideas?

helicoil

iTrader: (104)

you will most likely need new gears now as you have overtightened the pinion changing the bearing pre-load when re-installing the pinion nut

chicane

Overtightened the pinion nut... and looks like gears and bearings are in your near future.

JEB99TA

iTrader: (32)

Took it to a performance shop and it came back making the same noises ... don't think they looked at the rearend and that's the main reason I turned it in ... the noises coming from the rear. I guess they got side-tracked with the transmission problem and they shipped the tranny back to FLP to have it repaired again ... 2nd-3rd clutch packs were what I was told was wrong with it. Great having $1,000 worth of tranny work done, but, what the hell are other things which could be wrong with my car that causes it to make these friggin' noises. Does everyone else agree it's the pinion nut too tight.bearings? Gettin' really frustrated with this ****.

Wouldn't it make noise all the time if this were the case?

JEB99TA

iTrader: (32)

Well, I came home at lunch and put the car up on ramps ... added a small bottle of limited slip differential fluid to the rearend, then, I released the grease from P/H ROD and LCA ends by pushing in on the fitting valve on each end. Grease shot out the fititngs on a couple of them. Drove the car to work and it's my rearend. I believe what happened is when the shop replaced the pinion seal about 3 months ago, they tightened the pinion nut ... as a few of you indicated might have happened. I guess the squeaking, grinding, and crunching noises are the bearing and ring/pinion gears clashing when I turn slightly.

I confirmed where the noise is coming from by having my wife drive the car while I was riding in the back with the back seats out. I next laid on the car at each corner with my ear hanging over beside each wheel ... no noise coming from the wheel areas at all.

It's pretty obvious what happened now and where the noises are coming from. Now, I don't want to take it back to the same shop anymore, ever. The problem which I turned it in for never got resolved, even though I told them I thought the rearend was the problem and that the problem first began just after they replaced the pinion seal. If they screwed it up this bad, I'm afraid to let them touch it again.

When I had my stock 10-bolt, the same shop put in a shift kit. I had a heavy duty Eaton posi and a built 10-bolt with less than 45,000 original miles on the car. Picked it up from the shop and the 10-bolt grenaded less than 1000 yards from their shop. They built me the best motor anyone could ask for, however, when it somes to internal transmission and rearend work, it's obvious their guy doesn't know what he's doing. What would you do if you were me? It's probably going to be like the tranny, they'll say it was just a coincidence that it broke right after they fixed it it.

Do you think I should just cut my losses and take it to the dealership where if they screw it up they'll be obligated to fix it?
__________________

alamantia

iTrader: (10)

i say tighten the pinion nut a little and see if it goes away, here is a similar thread if it helps you any: https://ls1tech.com/forums/gears-axles/649465-replaced-rear-pinion-seal-now-have-whining.html

JEB99TA

iTrader: (32)

Thanks a lot. I'll tighten it down and see what it does ... believe my torque wrench goes up to 150 ft/lbs ... maybe higher.

JEB99TA

iTrader: (32)

Took it in and had it torn all the way down. Pinion preload was way off ... pinion nut rotational torque was way off, as well. Got an email back from the good folks at Strange and the guy indicated it was pretty clear the shop that had replaced the pinion seal had mess up the pinion preload settings ... after describing the symptoms in detail to him.

It's in the shop now getting a new crush sleeve collar. Should have it back tomorrow. Thnaks for the help ... you guys were right on the mark. The good part is nothing was damaged ... good part is it has a 35-spline rearend. I originally thought it was a 33-spline ... :-)

Disturbed Bird

iTrader: (9)

i had my seal replaced by them never had any trouble with it after that. maybe its because u have a strange rearend. JK hope u get it out soon need to get another race with ya before i hand this high school kid his *** in his mustang

JEB99TA

iTrader: (32)

Hey Josh! What's happening? Yeah, NLP replaced my pinion seal two other times in the past year and I never had any problems, either. Geoff has a good shop and he has always done good by me ... so has Mike Norris. Next Level Performance is a good shop.

I don't know enough about rearends to comment on the rearend issue. The white paint mark where they marked the pinion position was about 1/4" off ... maybe it backed off on it's own or maybe somebody just had a bad day. I just really don't know, but, it doesn't matter much. I'll still be using the shop ... probably going to get them to do my nitrous setup soon. I was up there talking to Mike about it the other day. Fortunately, there was no other damage and they expect to have it together and back to me for the weekend.

That being said, I'm game for going out to the 'back 40' where it's safe and we'll run 'em so I can beat you again before you bear down on the Mustang ... lol! j/k

Last word of advice because I would hate to see you kill your motor. With the stock fule lines and RaceTronix fuel pump, you're probably leaning out your motor already ... 150 shot is pushing the fuel supply to it's limits ... IMHO. Before you spray it anymore, I would get it checked.

Disturbed Bird

iTrader: (9)

i asked mike he said it was alright and i didnt need to step up my fuel injectors. but i dont know about that. i think i do need new injectors

JEB99TA

iTrader: (32)

150 HP shot is pushing the fuel supply to the limit. Too many expert tuners here will tell you it is. I'm not speaking of fly-by-might tuners. Ask some of them ... if I'm wrong then I stand corrected ... just ask a few of them how a Racetronix pump will pump enough fuel through stock lines to support 600+ RWHP. Stand alone fuel supply would prob kepe you plenty safe ... maybe race gas, but, high octane I was told is more for race-buily motors and that it might our motors more harm than good. What size injectors do you have?

Disturbed Bird

iTrader: (9)

stock 28's i think i need bigger ones but mike siad there fine. im going to get them anyways to be safe