Corvette C4 autotragic question

I've just got one of those phone calls from the local Chevy emporium who were looking at why my '87 C4 is currently doing an Exxon Valdez impression with its transmission fluid. It looks like one of the two major leakage points is the dipstick tube (the other one being the transmission pan). I think it was mentioned that the trans has to be taken out to take car of the dipstick tube leak, or was I mistaken?

I guess fixing either leak will require access to a lift even if the trans doesn't have to come out which means I'll have to pay someone to do the work . Oh well, it was time to lay it up for winter anyway...

Correct. There is even less room on those then the 3.4DOHC found in the 95-99 Monte Carlo's.

Brian

Thanks, even though that wasn't what I had hoped to hear. Looks like between the aircon compressor that lunched itself, the necessary R134a conversion because nobody around here seems to work with R12 anymore and the transmission issues, I'm looking at a 2 grand bill.

Miata, I know it would've made sense to buy one.

seriously - trans out to pull dipstick tube up some and swap in a new rubber?

go ask one of the vette forums. someone out there has done without dropping trans i am sure.

if you don't have one, a cherry picker is a couple hundred dollars.. the motor and trans can be out and sitting on the floor in a few hours. doing it this way might actually be easier than just pulling the trans from underneath.

then it's just a matter of silencing that voice in your head that says "while it's apart i might as well..."..

C4's are cheap... if you do your own work. If you don't.... well... welcome to expensiveville. Makes having a BMW repaired look almost reasonable.

I knew a guy that let his sit for several months because it needed a battery. I really like C4's, but it has a few maintenance challenged areas.

There's got to be a hole that you could cut in the floor to make this repair happen.

patgizz wrote: seriously - trans out to pull dipstick tube up some and swap in a new rubber? go ask one of the vette forums. someone out there has done without dropping trans i am sure.

Good point, might as well do that, too. Trouble is that I have to get underneath it anyway to do the transmission pan and we're back to "I don't have access to a lift". OTOH this might be a good excuse to go and check if the guy advertising knee-high lifts still has one left.

racerdave600 wrote: I knew a guy that let his sit for several months because it needed a battery. I really like C4's, but it has a few maintenance challenged areas.

That's another fun job, but fortunately not quite in the same league as pulling the trans to swap a piece of rubber.

As a former C4 owner, I agree with 2 points made on this thread: 1) there is someone on the corvetteforum who can probably help you, and 2) paying someone else to work on a C4 will make Ferrari ownership seem reasonable.

That said, I removed the manual trans from my 89 myself using only jackstands and a transmission jack from Harbor Freight. So it can be done. You will need to drop the exhaust, and remove a beam that attaches the tail of the trans to the diff, but that is just tedious more than difficult. Once out, the automatic used in the C4's is a typical GM unit used in a number of other vehicles (unlike the manual).

And about the battery - I used to tell other cars guys that the Corvette is so difficult to work on, you have to remove the front fender just to replace the battery. And while that is technically true, because of the clamshell hood, the "front fender" on a C4 is just a small piece of plastic held on with a dozen or so torx bolts. So it sounds a lot worse than it really is.

Is there ever a real reason that you need a vehicle lift? I know I want one, but I also want to have sex with super models, and I don't think either will be happening soon. The heavier the jack stand the taller they'll be; my dad has some heavy duty jack stands that can hold a jeep frame at waist height (I forget the tonnage rating).

post script: Replace super models with Victoria Secret Models due to others' comments.

novaderrik wrote: the motor and trans can be out and sitting on the floor in a few hours.

Have you ever worked on a C4 Corvette? If you can do this without an axe and cutting torch, I've got a job for you.

I guess it depends on your definition of "a few".

MCODave wrote: That said, I removed the manual trans from my 89 myself using only jackstands and a transmission jack from Harbor Freight. So it can be done. You will need to drop the exhaust, and remove a beam that attaches the tail of the trans to the diff, but that is just tedious more than difficult. Once out, the automatic used in the C4's is a typical GM unit used in a number of other vehicles (unlike the manual).

Don't forget the massive crossbrace under the car (my C4 is a convertible)...

In 3 or 4 years of C4 ownership and haunting the C4Tech/Performance board at the Corvette forum, I NEVER heard of anyone separating the body from the drivetrain for regular service. It's just not that hard to get the engine/transmission/rear end out to justify it.

I know they were put together that way in Bowling Green, and that you could do it if you really wanted, just never heard of it being a normal thing.

Now on a late-model Ford Superduty, that's another story...

I've pulled both the auto and the ZF from various C4 coupes. You don't need to drop the trans to replace the dipstick grommet; there is a tube brace topside in the engine bay; unfasten it and you should be able to remove the tube from the pan and replace the grommet. Will probably be easier to persuade it out from the bottom and for sure needs to be put back in place from underneath. In coupes, nothing absolutely has to come out to replace the trans pan gasket, though it's nice if the exhaust is out from the front-section back (after the precats on the L98 or cats on LT1). A word of caution: be very careful not to over-tighten the pan bolts because the case is aluminum - spec is 10 ft-lbs or less, so hand snug is plenty. Life will be easier for you in the future if you ditch the factory gasket for a fel-pro. OTOH, you have a vert, so dunno about the x-brace, haven't spent any time under a vert. Both jobs will be much easier with a lift but can be done on jackstands.

RossD wrote: Is there ever a real reason that you need a vehicle lift? I know I want one, but I also want to have sex with super models, and I don't think either will be happening soon. The heavier the jack stand the taller they'll be; my dad has some heavy duty jack stands that can hold a jeep frame at waist height (I forget the tonnage rating).

LOL.

I was thinking the same thing. About the lift, that is.

RossD wrote: ...I also want to have sex with super models, and I don't think either will be happening soon.

But supermodels are so skinny. I can't imagine the amount of cuts and scrapes from those sharp knees and elbows. Not to mention the bony hip bruises.

I hesitate to even say it because i havent done this on a c4, but i cant even picture an application where you would need to drop the trans to replace that dipstick grommet on a 700r4..

Although, if you are doing the pan at the same time, save yourself some annoyance and pop the thing out from the bottom once the pan is off. That really beats trying to get it out from the top with some kinda grabby tool if space is limited. The new one with some grease on it you should be able to pop back in with no more than the force of one finger.

Also, iirc the coolant lines are pretty much right above the dipstick grommet so id get a good visual on those and make sure THATS not where the fluid is coming from.

I've replaced the clutch on my '88 C4 on jack stands, and yes, it is a convertible. Fashion some short ramps out of 2x8's, just long enough for the tires to sit on. 2 boards thick will do. Now you'll have extra room to slide a jack under the car. Buy heavy truck stands as mentioned before and get the car up as high as you can. I raised each side a bit at a time to keep the car closer to level. In the end there was at least 18" of clearance. The x-brace bolts up at each corner and a couple of nuts in the channel toward the back. No big deal. Just make sure you set the stands in the right spot so you'll have clearence to get it out. The exhaust may have to come out to get access to what you need, but its not too hard with some long extentions to reach the manifolds. Just drop it as one big peice. If you decide to pull the trans, mark the C-beam on the trans and rear end before you start, it has to go back right where it was. Some prying and cussing will ensue, but it will come out. Buy a set of C-beam plates from ZF Doc, they will make it way easier to put back in. But like everyelse has said, I don't believe the trans has to come out. Just jack it up and crawl under there! Besides, how many Grassrooter's have hoists?