Question: Rear Main Seal info for 87 B2K

[VetteLee]

I've got my '87 in for transmission work - getting the overdrive replaced with a unit from S-K Speed in New York, and having the manual trans rebuilt, and getting a new clutch and flywheel.

The trans guy said the crank and flywheel is not standard for a 1987 (crank is forged pre 1987 he thinks), as he found after receiving the new flywheel which did not match the old one . I'm having him check into the source of an oil leak. If the oil leak is from the rear main seals, does anyone know what the setup is for this? Does the crank have to be dropped or? My trans guy seems to think the seals cannot be replaced simply from the rear of the engine with the trans out.

I called Callaway CT today, but got a receptionist saying everyone was in Las Vegas

Thanks,

Lee

 

[MagicDragon]

Hello Lee, Use the same rear main seal as the 69-80 chevy V8. I don't think you need to drop the crank. Those guy's at S-K are super...they have helped me with a few 4+3 parts in the past. I think WHEN I kill my 4+3 i'll put in a Keisler 5 speed- TKO-600 with the .82 OD gear. Good Luck with the repair!

 

[VetteLee]

Hello Lee, Use the same rear main seal as the 69-80 chevy V8. I don't think you need to drop the crank. Those guy's at S-K are super...they have helped me with a few 4+3 parts in the past. I think WHEN I kill my 4+3 i'll put in a Keisler 5 speed- TKO-600 with the .82 OD gear. Good Luck with the repair!

Thanks MagicDragon - nice pic!

I think the car will be ready this week. The trans guy didn't think there was much leakage around the seal, but something on the driver's side not visible from below might be leaking. Hopefully he can figure out where it's coming from.

I started researching other transmissions to replace the 4+3 but decided to stay stock especially since I don't drive it much (it has less than 16,000 miles). It seems like the transmission pros, including Brian at S-K Speed, don't have a very high opinion of the TKO's. I was considering a Richmond unit until I decided to stay stock.

Take care,

Lee

 

[MagicDragon]

Just curious, what happened to the trans at 16K that you need to rebuild the O\D and 4speed? I think you made a good decision to keep it stock. The only reason for me to want the Keisler 5 speed is because I get confused sometimes when in 2nd gear with the O\D enabled......it makes me THINK I'm in 4th gear and then I hit the O\D button and wham it feels like I slammed on the brakes. It just feels wrong to me. I hope all goes well and enjoy that beast!

 

[VetteLee]

Just curious, what happened to the trans at 16K that you need to rebuild the O\D and 4speed? I think you made a good decision to keep it stock. The only reason for me to want the Keisler 5 speed is because I get confused sometimes when in 2nd gear with the O\D enabled......it makes me THINK I'm in 4th gear and then I hit the O\D button and wham it feels like I slammed on the brakes. It just feels wrong to me. I hope all goes well and enjoy that beast!

The O/D was slipping and the trans guy said the fluid was pitch black, signs it had been overheated. The 4 speed sometimes popped out of 2nd gear. Brian at S-K Speed said that popping out of 2nd gear is usually an indication of problems in the O/D. My trans guy said these 4 speeds were known for popping out of 2nd and that there were some upgraded parts he could install as part of a rebuild that would prevent it.

I decided to get all the work done at once rather than taking a chance and needing to go back later for another round of repairs. The S-K Speed O/D units have some upgraded parts as well that were evidently not included with the stock unit that came with the 1987 Callaway (I called Callaway in CT to verify if the O/D units were stock Corvette or modified/upgraded units and they said they were stock).

I think the O/D is really only useful to me with 4th gear, so I'm thinking about making the activation all manual. I don't like the programmed operation, similar to what you've experienced. Chris Petris sent some instructions for disabling programmed operation via bypassing some ECU leads, and Brian at S-K recommended disconnecting the relay inside the engine compartment to accomplish this.

I may be getting the car back today or Monday. It should be in just about perfect mechanical condition now. The Corvette shop a few doors down from the trans shop solved a cold start problem I was having; They found a defective temperature sensor in the intake manifold that provides feedback needed to activate the "9th"/cold start injector.

Lee

 

[MagicDragon]

Good call on getting it all done at the same time. Please let use know how it turns out! I agree about using the O\D in 4th only and that how I normally use it. But there has been a few exceptions - and I usually get bit. I don't know what it is with me but I'm still to this day trying to put the thing in 5th gear. I've had so many 5 speed cars over the years...you know the saying about old dogsotfl Enjoy and for goodness sake put some miles of smiles on that thing when you get it back....you know you can't take it with you when it's your turn.... I've got 70K+ on mine and drove it to work today.:cool

 

[VetteLee]

Good call on getting it all done at the same time. Please let use know how it turns out! I agree about using the O\D in 4th only and that how I normally use it. But there has been a few exceptions - and I usually get bit. I don't know what it is with me but I'm still to this day trying to put the thing in 5th gear. I've had so many 5 speed cars over the years...you know the saying about old dogsotfl Enjoy and for goodness sake put some miles of smiles on that thing when you get it back....you know you can't take it with you when it's your turn.... I've got 70K+ on mine and drove it to work today.:cool

Thanks MagicDragon. My current daily driver and the last two were modern 6 speeds and before that it was 5 speeds.

I got a call from the Corvette shop today - they've been very thorough in looking for any residual oil leak and verifying the car is starting when "cold" every morning for a few mornings in a row. I should get it back on Monday, possibly with it set up for manual only overdrive operation.

I definitely need to get it out a little more - maybe a little drive is on order over the next weekend .

Lee

 

[VetteLee]

Got it back on Monday

I got it back on Monday and based on my drive back home and a short drive a couple of days later I am happy with the results. The manual shifting action is much improved and overdrive operation is more positive.

The manual bypass for overdrive didn't get done. I'm going to drive it as is for a while then decide if I want to go that direction. The Corvette shop said the Overdrive is not designed to be operated while in first gear since there is no/insufficient pump pressure taking of from idle and therefore there is possibility for damage if this were to occur. I'll talk to Brian at SK Speed to confirm.

I do notice a little shudder when the clutch is gradulally engaged - my trans guy tells me this is not unusual with a new CenterForce dual friction clutch and that it should diminish within the next couple thousand miles (which is a long time based on current miles driven per year).

The only thing bothering me now is a section of carpet that sticks out a little on the left side of the clutch pedal. Someone worked on it while it was in the shop, and it's a little better, but my shoes scrape against it when shifting which is annoying.

It seems that the oil leak may be gone - I'll have a better idea after it sits for a while. Maybe it was coming from the trans or?

I'm going for a drive over Ortega Canyon tomorrow to meet a friend with a supercharged 2001 Z06 .

Lee

 

[MagicDragon]

Glad to hear you got her back. I put a stock clutch back in mine-that's when I took the pic. Mine grabbed a little in the beginning also. It should smooth out with the more miles you put on. If your oil leak continues you might want to check the PVC lines under the intercoolers, they might be flattened out and then the oil gets pushed out from area's it's not supposed to be. Enjoy the ride!!!!

 

[VetteLee]

Glad to hear you got her back. I put a stock clutch back in mine-that's when I took the pic. Mine grabbed a little in the beginning also. It should smooth out with the more miles you put on. If your oil leak continues you might want to check the PVC lines under the intercoolers, they might be flattened out and then the oil gets pushed out from area's it's not supposed to be. Enjoy the ride!!!!

Thanks MagicDragon.

The weekend drive has been postponed to this Saturday.

Callaway Cars West checked the car out a few months ago and replaced the intake seals which were leaking oil, so hopefully they covered any issues with PVC lines.

What kind of clutch did you have in it before?

Lee

 

[89onlyZ51]

The manual bypass for overdrive didn't get done. I'm going to drive it as is for a while then decide if I want to go that direction.

I'm surprised your OD isn't already manual-only operation. In my Callaway supplement to the owner's manual for '87, it says that the auto-engage logic for OD has been disabled in the chip. I've read my chip out and verified that this is true (essentially set to auto-engage at 255mph or something like that.). If you send me a blank chip and adapter, I'd be happy to make a copy for you as I feel that's a better way to bypass the OD logic than messing with the wiring.

Tom

 

[VetteLee]

I'm surprised your OD isn't already manual-only operation. In my Callaway supplement to the owner's manual for '87, it says that the auto-engage logic for OD has been disabled in the chip. I've read my chip out and verified that this is true (essentially set to auto-engage at 255mph or something like that.). If you send me a blank chip and adapter, I'd be happy to make a copy for you as I feel that's a better way to bypass the OD logic than messing with the wiring.

Tom

Thanks Tom,

My addendum on Page 17 under Transmission Overdrive says: "the control switch for the transmission overdrive has been modified so the overdrive will remain in whatever mode has been manually selected, whether the iginiton switch has been switched off or not. (see pps. 5-6)".

I'll drive the car around and see if I can figure out what the exact behavior is. Maybe I'm putting it in overdive when cruising, and the programmed operation continues from there. It sounds like if the car was in OD mode and turned off, it will be in that mode when it is restarted.

Lee

 

[dknight]

Hi guys, I have 87 convertible with the 4/3 and would love to be able to turn off the overdrive until I need it after 4th. My 'switch' does not work so I assume that the next thing to do is to replace it...? But it sounds like there is some programming that can be done? I would like to hear more on that. Will it still go into od after 4th?

I drive mine every day...lovin it right now with the top down!

Thanks

David

 

[89onlyZ51]

Hi guys, I have 87 convertible with the 4/3 and would love to be able to turn off the overdrive until I need it after 4th. My 'switch' does not work so I assume that the next thing to do is to replace it...? But it sounds like there is some programming that can be done? I would like to hear more on that. Will it still go into od after 4th?

I drive mine every day...lovin it right now with the top down!

Thanks

David

You would need to fix the switch and/or any relays that may be faulty. In the chip you can set the parameters for automatic OD engagement, or prevent it from engaging automatically alltogether. On mine, OD only engages when I press the button (still in gears 2-4) and automatically disengages when I come to a stop.

 

[MagicDragon]

When I replaced my clutch it was the original, I ordered a plain jane (Sachs) no frills replacement from the local parts store..because I want the clutch to be the weak link. After removing the old clutch and comparing the two- they were identical right down to the stampings, paint markings....and Sachs name was no where to be found on it. Strange but true. It's been working like a champ for the last 10K miles.

dknight- the O\D switch went bad in mine a few years ago. The switch is a momentary push switch that I found at Radio Shack for 2 bucks. The switch is easy to access once the shifter console is removed. My O\D is manual however under the right conditions it has switched in O\D on its own in 2nd gear at extreamly low loads at very low RPM- doesn't happen often-hehe. Have fun and I hope everyone is enjoying their Callaway!