LS1GTO.com Forums banner

1 - 20 of 39 Posts

·
Registered
Joined
·
73 Posts
Discussion Starter #1
Sorry if this is in the wrong section.

Got the Reduced Power issue sorted and after numerous WOT pulls, started seeming plumes of smoke out the back of the car. It was intermittent though. Oil level is fine, almost no oil in my catch can. Really surprised me today when smoke started pouring into the cabin from the transmission tunnel area. Now I was thinking maybe the clutch was slipping, but absolutely no issues with it holding all the way to redline. Opened up the shifter area and was met by glops of grease and some oil (mainly grease, like bearing grease - transmission is filled with Pennzoil Synchromesh). I figured this is the issue, seeing as I could see down to the exhaust and some oil residue getting on there. Now, where is this grease coming from?

My best guess is that an internal seal in the shifter itself has let go and is slinging grease? But, I don't see how a shifter can "sling" grease seeing as there's no rotational parts in it. Could it be the input shaft bearing? Is there enough grease in there to sling all the way up and coat the shifter, the insulation and creep up even onto the shifter itself (there was a good amount of grease). Looking at the input shaft from up top, I only saw a light coating of oil on it, absolutely no signs of grease. The grease was coating the top of the shifter, insulation and part of the shift lever ... nothing really below. Where else could grease potentially be coming from if not the shifter? Or am I wrong in assuming that grease from the shifter can't get shot up to areas where I'm describing?

Wish I had taken pictures but I was too preoccupied with trying to clean everything up and figuring out where the heck it was coming from to think to snap some pics. It's an MGW-P with no issues that I can tell shifting into gear.
 

·
Premium Member
Joined
·
35,704 Posts
Usually, though, the rear trans seal goes bad snd you get oil sling around that area. What you describe seems a bit excessive, though.

Under the shifter itself where the offset lever and shift rod is at, is a small port that goes right to the rear bushing, i think. The nose of the yoke and the ouput shaft end is rotating around in there. It likely slings oil around. If you have a bad shifter seal, i'm sure it will work it's way out.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #4
That's what has me scratching my head. I've had a grease packet in a CV joint let go and it slung grease all over. If it was just oil, ok, definitely gonna be the shifter seal and probably oil making its way down to the driveshaft and slinging. But, grease?! There's some oil for sure that coated parts, but then there was a dark brown grease also coating everything. My kneejerk reaction was, "great, shifter opened up and allowed the internal grease to leak." But, there's no sign of it on the driveshaft, and how the heck was it creeping up?

It's late now, but I'll take pics of the actual grease to show that it's definitely not just "dirty oil." It's has a tackiness like grease, not slick like oil (even when dirty). C8's are looking real good. LOL.
 

·
Premium Member
Joined
·
35,704 Posts
oil generally isn't just made of one molecule. sometimes the more volatile components go bye-bye, especially at elevated temperatures, and what's left is the thicker stuff.

that's just a hypothesis.
 

·
1 of 40,757
Joined
·
6,226 Posts
If the trans trans output shaft and driveshaft yoke are heavily greased it will spray a lot of it off the yoke when the grease becomes thinner from heat. Of course, once the extra grease is slung off it should stop. If you have A LOT of grease on the underside of the car around the shifter it may be something else.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #7
Alright, so it's definitely not the shifter. Pretty sure it's a seal in the transmission, likely the input shaft seal(?). Jacked up the front of the car (wanted to do the entire car but I couldn't find my fourth jack stand ... shrug. Went to jack up the transmission to undo the transmission mount and noticed transmission fluid leaking out and creating a small puddle on the ground. When I finally crawled under, I noticed a healthy coating under the car and plenty burnt on the exhaust (hence, the smoke). Snapped some pics. I would say it's most definitely the seal, but the only thing that has me scratching my head again is that the rubber donut/bushing directly behind it is completely dry. And I mean it doesn't have an iota of oil on it. I'd think that driving at a high rate of speed, it would get SOME splash on it, seeing as the entire surrounding area is covered in it. Anyone have any other possible suggestions?

Also, how hard is it to replace this seal (if it is the root cause)? Can it be replaced with the transmission still in or does it have to get dropped down?

Pics:

#1. Transmission tunnel from the top. Note the dried and tacky oil running around the perimeter of the opening.
IMG_1231.JPG


#2. Snapped another pic inside the tunnel from the top.
IMG_1232.JPG


#3. You can see where oil has been hitting the exhaust at the X-pipe and burning off, leaving crud on the exhaust. That sheen you see all over is oil. Yea, it reached pretty damn far. Here you can sort of see how dry the driveshaft donut is.
IMG_1235.JPG


#4. Bottom up. Donut is completely dry. It may look like that's some oil on the far side, but it's just the camera. It's literally completely dry. You can see how oily everything else around the seal is though. I'm assuming that seal right there is the culprit?
IMG_1238.JPG
 

·
1 of 40,757
Joined
·
6,226 Posts
The oil looks thin like trans fluid. Considering the drip building up at trans tail case I’d say your output shaft bushing is shot. Edit: I meant the trans Rear Output seal.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #9
The oil looks thin like trans fluid. Considering the drip building up at trans tail case I’d say your output shaft bushing is shot. Cheap and easy.
Can it be done with the transmission in place or does it have to come down?
 

·
Premium Member
Joined
·
35,704 Posts
Lulz consult ls2-Gto's thread about the bushing install.

Input shaft seal is on the other end. Easy to replace--much easier than the output shaft bushing.
 

·
1 of 40,757
Joined
·
6,226 Posts
I’m an idiot. The seal.
I got mine off amazon for $17.
Easy: pull the drive shaft. Remove old seal and tap in the new one. I used a large socket.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #13
Okie dokie, so, did the seal today. What a pain in the arse, thanks to my exhaust. Not really, I just figured it was going to be less than an hour job and it turned into about 2. All my own fault and my "custom" exhaust. Anywho, just wanted to confirm. Last time I gave enough of a shit to change the transmission fluid on the M6, it was 4.6qts into the reverse light switch. Looking it up online, it seems it has changed to "fill until fluid comes out of the switch hole?" Is this true? I did and the transmission seems fine.

On an aside, when I pulled the fill plug from the FILL hole, nothing came out. Jeez. Transmission was just starting to feel a bit notchy, but I didn't think it was that bad.
 

·
Premium Member
Joined
·
35,704 Posts
I knew someone whose wife filled the engine up to the top of the valvecover with oil. Engine didn't survive of course.

I'm sure someone had backup switch hole and factory fill hole mixed up in their head, if only partially. I do that kind of stuff all the time.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #15
I knew someone whose wife filled the engine up to the top of the valvecover with oil. Engine didn't survive of course.

I'm sure someone had backup switch hole and factory fill hole mixed up in their head, if only partially. I do that kind of stuff all the time.
Post #5

Post #19
(this one shows the actual service manual - says to fill it up to the bottom of the switch hole, AKA fill it up until it starts coming out)

Is the new service manual mistaken?
 

·
Premium Member
Joined
·
35,704 Posts
speaking of mix ups, i read/typed "backup switch," but had "reverse lockup solenoid" in my head, lol. imagine trying to fill that up until even, LOL. (i should tell you a story of when i had park and neutral switched around in my head when i installed and "aligned" a p/n safety + gear position sensor on a fr0d... boy was that embarrassing.)

i've never filled it through the backup switch hole, honestly. i've always drained and refilled through the shifter area (same area the reverse lockout switch solenoid feeds into) and measured the amount i put in. IIRC i've always filled by amount and not simply "up to the line." i think the only thing i've done method with on either car is with the rear end...

anyway, as long as you measure, you should be fine even if it isn't dead even with the hole. if the car isn't level you might end up putting in more/less of the amount you desire if you try the "fill to the bottom of the hole" method.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #17
That's just the thing, I didn't measure out the fluid. I popped the fill plug hoping there'd be some left and I could just fill up just under a quart of Synchromesh and it would be good to go. When none came out, I popped online to re-affirm my previously held belief that the transmission took 4.6qts. That's when I came upon the "new" service manual calling for the fluid to be filled to the reverse light switch. The car was lifted up on a two-post lift that I have access to on Sundays, so it's level. After filling it up, transmission does shift nicer than I can ever remember, but I don't want to damage anything either. I'm torn as to what to believe now ...
 

·
Registered
Joined
·
73 Posts
Discussion Starter #19
Well, good news is, it probably is down to 4.6qts now. Problem remains. Did a few blasts on service roads and all looked well. Then a couple more and saw a plume of smoke out the back. Few more times and slight smoke. Just to be 100%, went to an open spot that I know has a decent incline and hit it and was greeted with a giant plume of smoke out the back and it continued to smoke as I drove around. Fuck this car.

Anyone have any clue what else could be leaking? The seal was installed and seated all the way in with a large socket. AC Delco part was used. I'm highly doubtful it's the output seal (probably wasn't in the first place). Has to be coming from that area though since it's kicking onto the exhaust causing the smoke.
 
1 - 20 of 39 Posts
Top