Leaky butt just in reverse.....
Thread Starter
Instructor
Joined: Apr 2006
Posts: 145
Likes: 14
From: West Chester PA
Leaky butt just in reverse.....
Weird question here. I am having the symptoms of the well known issue of the leaky butt on the rear diff of my 98 vert, but it is only when i reverse out of my garage. Its not on the floor of the garage, just on the driveway out side the garage. And it only seems to be when the car is cold and has been sitting over night. This is on morning starts. So my question is do we think its the diff or the trans since its only in reverse that i can report the leakage? Any feedback would be helpfull! Thanks.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Somehow I doubt it's only happening in reverse.
Jack it up and have a look. The leaky butt is a very easy diagnosis. You'll see dried up black grease crud covering the lower half of the pumpkin side cover (maybe more) with probably some fresh drops right at the bottom.
For your sake I hope that's what it is. Leaky butt is an easy fix. Tranny seal is a bit more involved.
Jack it up and have a look. The leaky butt is a very easy diagnosis. You'll see dried up black grease crud covering the lower half of the pumpkin side cover (maybe more) with probably some fresh drops right at the bottom.
For your sake I hope that's what it is. Leaky butt is an easy fix. Tranny seal is a bit more involved.
Thread Starter
Instructor
Joined: Apr 2006
Posts: 145
Likes: 14
From: West Chester PA
If it is the diff leak, why would it only be durning cold starts and if I were to get it fixed by the stealership, how much would they charge? I also saw that there is a vent on the top of the diff that may be clogged , could this be casing a buildup of pressure resulting in the leak that I am noticing?
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
If it is the diff leak, why would it only be durning cold starts and if I were to get it fixed by the stealership, how much would they charge? I also saw that there is a vent on the top of the diff that may be clogged , could this be casing a buildup of pressure resulting in the leak that I am noticing?
Thread Starter
Instructor
Joined: Apr 2006
Posts: 145
Likes: 14
From: West Chester PA
Ok, My garage is perfectly flat and there are no drops of any kind in the garage. Then I reverse out in the morning, today the temp was 55, and my driveway is very slightly slanted downward. Then I notice a puddle about the size of a baseball under the car. But when i check it throughout the day very closely and no leak at all. I am hoping its just over filled or something small.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Park on a level surface and remove the diff fill plug. The lube should be pretty much level with the bottom of the hole. If it pours out, then it was overfilled which happens a lot when guys fill the pumpkin while the car's azz is in the air. I doubt that's your problem though because an overfill is only going to puke out of the vent after some spirited driving.
A baseball sized puddle is a pretty fast leak IMHO. You need to get under there and look for yourself. What color is the puddle? Most ATF is going to be reddish whereas the diff lube is going to be golden (and much thicker). Throw some white sheets of paper under there if in doubt.
A baseball sized puddle is a pretty fast leak IMHO. You need to get under there and look for yourself. What color is the puddle? Most ATF is going to be reddish whereas the diff lube is going to be golden (and much thicker). Throw some white sheets of paper under there if in doubt.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
Park on a level surface and remove the diff fill plug. The lube should be pretty much level with the bottom of the hole. If it pours out, then it was overfilled which happens a lot when guys fill the pumpkin while the car's azz is in the air. I doubt that's your problem though because an overfill is only going to puke out of the vent after some spirited driving.
A baseball sized puddle is a pretty fast leak IMHO. You need to get under there and look for yourself. What color is the puddle? Most ATF is going to be reddish whereas the diff lube is going to be golden (and much thicker). Throw some white sheets of paper under there if in doubt.
A baseball sized puddle is a pretty fast leak IMHO. You need to get under there and look for yourself. What color is the puddle? Most ATF is going to be reddish whereas the diff lube is going to be golden (and much thicker). Throw some white sheets of paper under there if in doubt.
Bill
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Instructor
Joined: Apr 2006
Posts: 145
Likes: 14
From: West Chester PA
Ok, I think i got it. At least im going to cross my fingers on this one. I backed the vette up on Rhino ramps and got underneath it . I noticed that it was missing one transmission pan bolt and it seems like that was the side were the majority of the oil was leaking. I got a replacement bolt and cleaned the heck outta the underneath with brake cleaner, so that i can monitor it over the next couple of days or so. 
