firetpi

iTrader: (1)

Hey there guys, I need a opinion on what i should do. This is a long one, get ready haha.


So i decided to purchase a 2001 Pontiac trans am ws6 a4 (48,000). Long story short, i got a good deal. Before purchasing the vehicle i test drove it but i didn't drive it over 60, it had a brand new rebuild on the rear differential. Again, long story short I picked it up drove it home on the highway and low and behold the rear end whined between 60-70 mph with your foot on the gas. I wasn't worried because the shop that rebuilt it gave the rear end a 1 year warranty.

Me being a mechanic freshly in the trade out of tech school, i figured it was setup incorrectly( or pinion bearing) That being the case it was under warranty. So i called the shop up, the owner said no problem it must be a bad gear set and he said he remembered it setup really good. First it took him 2 months to get the gear set because it was "back ordered" he said he used OEM Gear sets. Either way, i let him have the car. I gave him a week + a full tank of gas so he had no excuse not to road test it properly. He told me to take it easy on the way home and to give the rear end a few cooling cycles and he said last time he thinks it wasn't broken in properly.

So i drive it home on the highway at about 70 mph easily. Park it, let it sit for a few hours, Drive it on the highway again and start to notice a slight whine again, now i know some whine is normal... So i decided to let it break in and see what happened. I brought it in on a lift at my work and went to check up on it. And i find the rear end leaking out of the rear cover and the pinion seal. I figured this explained why the whining had gotten louder again.

I called the owner and explained to him it was leaking and whining again, He said he could seal it up but he couldn't keep putting gear sets in the car because it was a wholesale thing etc blah blah. So i finished that conversation because since i'm a tech/mechanic i understand where he is coming from but, i don't think its right since the job was done cheaper that it shouldn't have been done correctly and it seemed appropriate that the action i take now is to tell him to rebuild it and get it right. Other wise i should take it to someone who is able to do it correctly and he can eat the bill. I don't think there is any excuse for that rear end to have a whine coming in, on a factory set OEM gearset Etc.

Thoughts/opinions! Please! Its tough because i don't want to be a jerk but i feel as though i'm getting fucked.

I will post pictures of the leaking rear end shortly

ssvert99

iTrader: (26)

a OEM gearset shouldn't make that much noise, so i'd guess break-in may be the problem. 70 mph highway speed on the initial break-in is not recommended. this puts alot of heat on a fresh gear... not good. recommended break-in is minimum of 3 short heat cycles(10 miles or so and cool off time) at in-town speeds(under 55), no clutch dumps, no full throttle, no "sustained highway speeds". cool off time should be no less than 1 hour.
good luck with this. i'd say at this point to buy another gearset and install it yourself or have an experienced tech at your work do it.

firetpi

iTrader: (1)

Well he at least said he would fix the leaks.

Its under warranty so, I mean i dont have money for a gearset at this time as i have to pay a deductible since i hit a deer last week. Maybe i could throw luca's in it to shut it up until i can replace the gearset?

ssvert99

iTrader: (26)

a leak should definetly be covered. you can try some Lucas oil, but don't get your hopes up.

firetpi

iTrader: (1)

I have had luck with it in the past. Perhaps i will have him put some in with a Gear oil of my choice, What would you say is the best?

All Black SS

I got a question, since you are a mechanic and all. Why didn't you just pop the cover off grab some marking compound and see for yourself if the gears were set up right?

I think everyone will agree that an oil leak will not cause noise until it has ALL leaked out.

Don't bother posting pics of it leaking. If you want to do somthing worthwhile, take a pic of the contact pattern.

I can't believe you took school for this and don't know?

firetpi

iTrader: (1)

Heres the problem with doing that, Why should i void my warranty. Touching the rear end myself would be retarded. Why would i want to cost myself money and or hassle in the end??

Its covered for a year. Could i sure and, if it comes down to the fact that i have to do it myself and itll be done correctly. Not to mention since its a daily driver on top of the fact its covered so why should i bother and cause a potential argument against my claim of it not being setup right etc? Obviously me popping the cover of will not harm or **** with anything in anyway but thats just one thing he can say.

But, At any point. The reason i asked is because I dont rebuild rear ends and i figured i would receive some useful info from people who have more experience in Differentials then i do. Seeing as the nature of these cars is to make them grenade, In school i did rebuild a 7.5 10 bolt out of a 97 ss but thats besides the point i thought perhaps the leaking pinion seal could have caused the pinion bearing to dry up and potentially cause it to self destruct.

Bassicly i was grabbing at straws because of the nature that im on both sides, I can see where he is coming from that he can't just toss gearsets in the thing. But on the other hand when i picked up the vechicle i asked him if it was ok if i drove it home on the highway easily (Only way home that i knew) at about 65-70 and he said yes no problem let me know how you make out. Honestly seeing as it was a comeback under warranty I would have cycled the rear end as much as possible before the customer received the vehicle, do i understand that he is busy? Yes but since it was a COMEBACK i would have thought he would have payed more attention to it. Seeing as he got a week and a full tank of gas, If he said he needed longer he could have kept it. He only drove it about 20 miles and he said he didnt even take it on the highway.

Thanks, Steve