Clutch Fluid Leak, Transmission Slip

[1Bad86]

Clutch Fluid Leak, Transmission Slip, What Clutch??

My '86 with a 4+3 Trans. has developed multiple problems. First, I have hydraulic fluid leaking inside the car down the clutch pedal onto the pad. Second, all of a sudden now when I accelerate the engine revs up first for a few seconds then seems to catch and go. Only seems to do this in 3rd through 7th gear. Anyone have any thoughts on the actual problems without shotgunning parts at it?

 

[Agent 86]

Sounds like the seal in your master is gone and your clutch disc is on it's way out. The leaking master may have contibuted to improper clutch usage resulting in glazing the disc or eating up the last of it's life.
Good Luck

 

[Rowdy1]

I Don't Know...

Much of anything about the 4+3 but from what I've heard, they're problematic. An uneducated guess would be the clutch disc also has fluid on it and is slipping in the higher gears. Good Luck

 

[1Bad86]

Thanks for your input guys. Your thoughts are the same as mine. The 4+3 does seem problematic, but it looks like mine has other issues. And BTW that is one sweet '62.

 

[Rowdy1]

Thanks

It's been very good to me, someday I'll get the stress cracks done which will make it look as good at one foot as it does at 20 Problem is, the way it runs and the way I drive it, I doubt I'll ever get rid of them.

 

[Hib Halverson]

The Doug Nash (what some in GM used to call the 4+3) is problematic from the sense that the electro-hydraulic overdrive is a POS. The gearbox section of the Doug Nash is pretty good and is a version of the Super T10 four speed now sold by Richmond Gear.

However, the problems discussed in this tread probably have nothing to do with the transmission.

I'd replace the clutch disc and T.O. bearing. If the pressure plate is severly worn or damaged, I'd replace that, too. The flywheel may need to be machined or replaced as well. While you have all this apart, inspect the pilot bushing in the crankshaft. If it's worn, replace that, too. OE-type bushings work well, but the roller bearing pilot from GMPP is the best choice.

Lastly, replace the clutch hydraulics...both the clutch master cylinder and the slave. After replacement, bleed the system per the service manual. Use GM hyd. clutch fluid and, not brake fluid. That will keep the clutch master from squeaking.

 

[TriTown]

Clutch

Yup, you have a clutch issue. I would like to add a bit of experience to the mix here. I do all my own work and just for the records I used to be an ASE registered tech a while back so I do know a little something...sometimes. I just did a clutch on my 85. It's quite a stuff the way GM got it all up in there. With some swearing and prying the job took me a week end. I also replaced the clutch master and the slave. Here is where I let my pocket get the best of me. Insted of using the GM slave for $200.00 and the GM master for $300.00 I used the local parts stores version. I have never been able to get the pedal back correctly in weeks time I loose the pedal and I'm now on my 2nd slave. The 3rd will be a GM slave.

My point is...YOU GET WHAT YOU PAY FOR! If your going to do it you're self or have it done make sure you get OEM parts. You'll pay but it will work the fisrt time every time. And don't cheep out! Once it's all on the floor replace it all with GM stuff. I did reuse my flywheel but eveything else is new.

Good Luck
Joe

 

[1Bad86]

Wow, lots of good info. Thanks for all of the insight. I too, believe you get what you pay for, thats why I use OEM or better replacement parts only. I also agree that this is not transmission related at all, as far as the T-10 and the overdrive are concerned (Thank you Lord). I'm going to replace all the parts you guys mentioned as well as the flywheel. I'm never going to sell this car, so why do I care if I have 15K in a 7.5K car.

 

[TriTown]

15k...7500

I'm sure that in time it will be worth the 15K, besides if you like the car cost has no real bearing. It's like hot rodding. Shoveling in more money makes it more fun for you in the end. You are building it for you and no one else!

 

[1Bad86]

Clutch Kits Hi-Perf. or OEM??

Well, It's become obvious I need a new clutch. I looked at MidAmerica and they have a kit made by LUK. I also looked at a kit made by CenterForce. My question is what kit is the best and are there ones I should steer clear of? I'm sure you guys have been down this road before. I'm also considering the Fidanza Aluminum flywheel. Any thoughts??

 

[WhalePirot]

you guys have been down this road before. I'm also considering the Fidanza Aluminum flywheel. Any thoughts??

Yes we have. Unless you like to throw money at it, why not have your stock flywheel inspected and surfaced, if needed, by a good shop?

The lightweight (aluminum) has specific application and may not provide the driving characteristics you like. It reduces rotating mass, allowing quicker revving. For the same reason, it reduces the amount of 'punch' your engine delivers when you launch.

I installed a McLeod and it is hard to launch smoothly, especially when hot. It really likes to chatter; has since day one, and has no leakage on it.

BTW, my experience with my 4+3, after 105k miles of moderate driving, was that the overdrive was fine, despite all the negative publicity. The 'Super" T-10 was worn out, with numerous cracked gear teeth and worn-through areas on many teeth, particularly second gear. It was maintained with Amsoil synthetic gear lube since I bought the car at 11,000 miles.

 

[1Bad86]

Thanks for the scoop on the flywheel. I think I'll take your advice on that one. I have modded the L98 toward low-end fun and don't want to be counter-productive. I've got 95K on it, so I'll be curious to check out the T-10. This is the first real major problem I've had with the driveline. I just hope mine isn't in too bad of shape. I do know that the Master Cylinder and and the clutch have

 

[Rowdy1]

I Agree

No need for a trick flywheel, for that matter a clutch either, unless you beat it pounding burnouts and slam the gears. A stock clutch and pressure plate will last just fine. I use Centerforce simply because of my driving habits in the 62.