Ok so ive been waiting on this manual black 99 A4 2.8 Quattro and for the past week they have been working on it, so far they have replaced the CV shaft, brake lines, clutch, and today they started to replace the rear main seals. But since the clutch was in i got to test drive it today. When i was test driving it was great pretty fast, rpms were all normal and clutch was smooth. We pulled over just to look in the engine and we popped the hood and burning oil was minimally coming out of both sides of the engine, left and right, it wasnt bad though, and the dealer said it would be like that before we test drove it because they havent changed the seals yet. The engine bay is very clean, and the interior is spotless, still smells like a new car. No accidents, and a 1 owner vehicle, with 81k miles, for 4500. So when we got it back to the shop they put it on the lift and we looked toward the back of the car and there was oil/grease all on the back gear box/ axel. I dont know if this is a big problem or not all i know is its concerning. I want to know if this car is worth getting or not, it also needs back rotors and pads. But i really need to know if the oil/grease on the back axel/gearbox is a big problem like do i need a new gearbox? please get back to me id like to keep this car and get it, the timing belt is going to need to be changed within the next 15k miles

 

I just did all three seals on the rear differential on my 99.5 A4 Q about 5 months ago. Mine was pretty oily looking too, but when I opened the fill hole and put my finger in, I was only down about a 1/4".

The big quesiton is, how much oil is still in the differential? If you've lost enough oil that the bearings have been dry, then you have a real problem. If you put your finger in the fill hole like I did and feel oil right below it, you're probably OK.

The front seal is a bit of a job. If its leaking from the half shaft seals, they're pretty easy to change.

 

mtroxel, any tips on changing that rear diff input seal? Mine has a leak that I'll be going after soon. I may just go ahead and do the axle seals just because, but I'm curious if you picked up any tips/tricks when doing the front seal. Thanks!

 

Yes, a few. I followed Bentley. Drain the diff, drop the drive shaft, remove the four bolts that hold the front assembly on to the diff. It should pull right out of the diff, input shaft included. Then you pull a little plug out of that assembly so you can get to a nasty little circlip that holds the input shaft in place. You need a good circlip tool and some swearing to get it.

I didn't use a slide hammer like Bentley says to get that shaft out. I put two of the drive shaft bolts back into the flange and used them to screw against the housing and draw the flange/input shaft out of the housing. They started digging into the aluminium housing so I put a couple of big washers between the aluminium and the bolts. Came right out.

That took me over an hour. Then I removed the half shaft bolts and dropped the diff to get those seals. If you just remove the bolt at the top of the rear hub carrier, you can pry the suspension back enough to get the half shafts off the flanges. Once the pumpkin is out, it takes about 5 minutes per seal. Might as well do them as long as the fluid is drained. They're nothing compared to the input shaft seal.

Assembly is reverse, blah, blah, blah. Just don't forget to hold the circlip in place as you slide the input shaft back in. Putting that circlip back in its groove is easy compared to removal.

 

Ok, so heres the update. I saw the car thursday and friday o last week. They have replaced the clutch, brakelines, cv shaft, valve gasket covers, didnt need the rear main seal to be replaced there was oil on the bottom front end of the car but it was from the valve gasket covers apparently. And there is oil on the rear differential, so they are currently replacing both rear axels, and putting new brakes and rotors all around. There also fixing the gas gage. Does everything that needs to be touched on ok? It has 81k miles and all in all it will be 5000 dollars. Thats with all repairs done.

 

Timing belt service should be done by 70k - that's from experience. I know the book says anything from 60-105k but you're better off close to 60k. My last tensioner failed at 57k miles of use (failed in the driveway - I was the .001% who had no damage from a tensioner failure). They can tell you the belt is fine - it probably is, but the belt isn't what fails. I've done probably 50 timing jobs and 1-2 max had any wear issues with the belt. All of them had the hydraulic tensioner piston at full extension, and many had signs of tensioner wear that would be leading to a valve-mulching failure. If they'll change the t-belt, serpentine belt, thermostat, water pump, hydraulic tensioner, tensioner roller, and idler roller, that car will be worth every penny of $5000, possibly more.

 

Id say its worth the 5k as is but try to squeeze the timing belt out of them.

 

I gotta ask you Gio, are you sure they're doing all that work? That's just a lot of work to do to make a $5,000 car.