5abivt

I apologize for not updating here since the photobucket debacle I did finally figure out a new site to host pics and I will update shortly. I will need to go through this whole thread and fix it from the beginning as best i can as well.
Also been working on some youtube content. recording simple stuff and editing etc. Not trying to make a living off a channel like every 15 year old these days but I figure it would be fun to document and share the stuff i do and plan to do.

But the only update that ill go into better detail in is that the clutch is out, everything was oil covered. Will update with pics shortly !

5abivt

Ok finally a break at work need to update this. Slowest clutch job ever still struggling for time but it’s getting there !

So, as some may have remembered last season I felt as though the clutch was slipping on occasion. Some videos had some hesitation on accelerating and I could tell the grip wasn’t there at the top end when shifting.
Finally got the trans out again and sure enough there is oil everywhere inside the bellhousing and on the flywheel and clutch disc. The clutch disk thickness is like new and the flywheel shows clear signs of contamination. I’m pretty sure I mentioned it earlier but I chose to go with the ram dual disc option from Jerry. And of course some pics :

Trans down and out. So so much easier the second time around. I had to keep stopping to triple check I wasn’t forgetting any steps ! The boot on the end of the slave was also torn do not sure if the oily residue was from the slave, the rear main or the input shaft seal on the trans.


Of course I did drain the trans fluid first. Lying under the rear of the zf6 full of fluid and removing it was a great experience the first time but I didn’t plan to repeat it


Bellhousing covered in oil !



Oily disc. They say metallic discs resist the oil way better than organic. Most likely why the car was still driveable and would pull hard and the slip was inconsistent


Thickness was pretty much new. Maybe 2-3k miles at best on the setup

95wht6spd

Let us know how you like the clutch.

5abivt

Ordered a metal alignment tool. I think it’s kind of sad that the ram dual disc doesn’t come with a plastic one as they’re pretty cheap but since I need to get my LT1 car back together next I figured it would come in handy and be worth the investment.


Shot of the rear main seal cover. Pretty cool that the main is setup like this and doesn’t involve the oil pan. Couldn’t find many threads on it so wanted to try adding pics and details for future reference if it may help. My bolts were tight , my gasket was also fine when removed so no evidence of an issue or leak from here yet.


Rear main cover removed.

5abivt

Most definitely will and am looking forward to it ! I would imagine it won’t be entirely different from the McLeod twin disc setup I had for my Lt1 car but that one had 2 solid hubs while the ram has a single solid and one sprung.

The rear seal comes press fit into the cover so it comes off with it. When I looked inside I was surprised to find this. It looks like dried black rtv inside the sealing area that seals against the crank. Not sure if this would cause an oil leak or not but I’m sure it’s not ideal. I thought at first the seal was dried up but I was able to wipe the black stuff out and the seal was fine. It could be rtv or oil I suppose.


Wiped clean.

1993C4LT1

Good work as always Mike And thanks for giving all the info.

A dumb question. Do you think the slip was due to to oil on the disc?

5abivt

Thx !! No doubt about it the slip was from oil contamination. Even the flywheel surface had an oily film on it. The clutch disc on both sides was oily too plus the bellhousing was covered in oil. Only question really is where did it come from.

1993C4LT1

I hate weird situations like that. Anyone have an idea why the oil was there? Hope the new RMS cures it.

A26B

Re: Source of Oil Contamination
If you will look at Mike's excellent picture of the inside of the bell housing, the most accumulation of oil residue is on the drivers side where the clutch slave cylinder is located. This is most likely the source.

Re: About the Rear Main Seal Cover Gasket
I'm not a fan of the OE style gaskets with a silicone bead on the gasket, applied with a silk screening technique. This gasket "feature" is responsible for coolant seepage into the 4 bolt holes of the Coolant Outlet Pipes. Very common to find the bolts rusted in place & broken when removed.

Likewise we see the same leakage associated with the 13 bolts holding the Crankcase Ventilation Box to the block, resulting in oil seepage into the bolt holes & ultimately allowing them to work loose. That's where the oily mess under the plenum originates.

Again, same thing with the oil pan gasket, common leaker.

The common flaw in the use of the silicone silk screening is that it is only applied between the bolts and does not seal the bolts against leakage. Although the silicone thickness is a very thin application it does add to the thickness of the gasket & does lessen the compression of the gasket where the silicone was not applied. Gasket compression from clamping forces is usually in the range of 12~15% of the uncompressed thickness. A 1/32" (0.03125") thick gasket would then compress about 0.004". If the silicon silk screening were applied to both sides at 1/2 mil (0.0005"), that totals 1 full mil(0.001"). That totals 25% of the gasket compression & results in unevenly distributed gasket compression. Over time, oil & coolant leak into the bolt holes when not isolated by the silicone bead.

Installation of new gaskets should always begin with careful cleaning to remove all residue and not damage the mating surfaces. Surfaces should be wiped down with a clean cloth or towel using a volatile, non-residue cleaner, such as spray brake or carb/choke cleaner.

Sealant, if any, depends on the gasket material & application. Not all gaskets require the use of sealants to be effective.

A26B

Mike, you wouldn't have been happy with the plastic alignment tool for installation of the dual disc clutch. Its too short & not precise enough to line up both discs properly. The precision alignment tool will do a much better job & provide for a smoother transmission install.

Also, FYI. Do not apply grease to the new fluted bronze pilot busing. The bronze is a porous "oillite" material impregnated with oil that will be exposed as the bushing wears, for self-lubrication. Applying grease will plug the bushing & not allow it to self-lube as designed.

95wht6spd

Hopefully it will engage smoother/softer, I have heard the old McLeod Street twin was strong, but like an on/off switch and would break things.

I have a McLeod RXT on my 02Z, and it is very nice. I think the RAM will be better than your old. I have a single Carolina Clutch stage 2 in my 95 and it has been very good, but would like to go DD when I change it.

5abivt

I’m glad I purchased it in the end it’s a solid piece and I’ll be using it again ! Question about the cover gasket do you reccomend any sealant with the install ? Have been debating on using a sealant to make sure it’s good and leak free. I know the bolts have been reported to come loose and I didn’t want that to happen this time. Thx for the input on the bushing. J did use a tiny bit of the amsoil moly grease. Seemed to work just fine but I may have used too much. The bushing I removed seemed perfectly fine and had some moly grease in the little grooves. I won’t be using any this time around on the bushing as I didn’t know it was ‘oilite impregnated’. Good to know !

The twin disc was really good that I can recall. Did chatter a lot but I loved it. Pedal effort was not much if anything over stock but it did come with an aluminum master cylinder as well so not sure how much that affected the pedal effort or travel. Few small updates coming up

5abivt

Forgot to comment on this but I sure hope you are right and the slave is/was the culprit ! I did have issues bleeding it from the start i wonder if I had been pumping brake fluid onto the pressure plate from the start !
I actually removed the factory slave to send it for a rebuild and ordered this Valeo unit so the car wasn’t a sitting duck. Long story short I decided the dual disc was the better option. It eliminates the fork, ball stud and slave all together and opens up a lot of options. Having been inside here 2x now I’ve learned the clutch setups are quite simple. A few measurements and there’s a ton of options to figure something out. I planned to go with a Mantic as they expressed interest to work with me on a setup that would be even lighter with a billet cover and such and I may follow up with that still but not yet.

5abivt

So, I tried tapping in the first rear seal into the cover using wood blocks. Basically the seal is a tight fit. One side can slide inside and leaves the opposite outer edge above the edge of the cover and if tapped will bend the seal. I bent it ever so slightly but it was enough to bother me so I ordered a new one. I did some research and asked a lot of questions on any reccomended methods and the one I felt comfortable with was using a hydraulic shoppe press. I don’t have one at home and called around for a few quotes to have a capable shoppe press itnin for me and the best quote was enough to make me consider just buying my own press. I know that bushings are on the to do list so I know I will find a use for it so I ended up just buying one.

While I waited for the new seal to arrive I decided to do a little work on the rear seal cover. It just looked like it needed polishing





Getting smoother

5abivt

Close up shot of the bronze bushing replacement. Lots of threads on bearings vs bushings and while I see the arguments for both I was more comfortable with the bushing. Have never had an issue with it before and there’s reassurance that if it fails it won’t destroy the zf input shaft. I stuck mine in the freezer for a few hours before tapping it into place.


Asked a lot of questions and got a lot of varied answers about crankshaft surface finish for the rear main. Might not have been too important but I spoke with Callies who made the crank for my LT4 and my engine builder Karl Ellwein and went with light sanding and scotchbrite pad for final finish. Pretty much everyone agreed too smooth of a finish was not optimal as the rear seal needs to wear in with the crank and can’t do that if it’s polished smooth. Yes I’ll admit I was tempted to polish it smooth

The crank had signs of contamination I’m not sure if normal From oil or if rtv was used (hence the thick chunking in the seal that came out) but I cleaned it up nice.


I used assembly lube (I’ll get the name) to lubricate the seal into the housing and in the press it took literally 30 seconds and it went in nice and straight. Once flush I used the first seal I had on top to press the new seal about 1mm further deeper than the seal that was removed.


Finally ready for install.

Joe_Joe

WOW. What an awesome build. This is the perfect setup for a C4. Kuddos my friend.

combatdoc

Rear main is just like LS style, I always put a small coating of RVT around the outside of seal before pressing it in the rear cover, that might explain why you were seeing some. I do this on atleast 10 engines a year and have yet to have issues. I got the ram dual disk with updated slave for my car, hope they work good, good luck.

erikszr1

so what does the updated slave cylinder consist of, part # ? im going to do the clutch master also. Thank you in advance!

5abivt

Thanks very much !

I can see using it on the outside. But my seal had the inside of the seal lip full of it. I mean it could very well be dried oil or stuff or rtv and may not have had anything to do with the leak but I’m glad I changed it out anyways. The LS has a great deal setup with the cover watches many vids on their replacement justfor the hell of it !

Just to mention it others have guessed my slave was the culprit in my situation. I also now believe it to be the case. It’s a replacement slave by valeo but made in China likely and cast aluminum. I would suggest NOT buying one of these and have your oem steel version rebuilt. I actually had my original removed so I could send it out for rebuild but I ended up changing my mind and deciding to go with the new conversion. My point being that the new ‘conversion’ eliminates the original slave and involves a hydraulic throwout bearing that goes onto the trans input shaft and requires drilling a hole in the bellhousing as well. Not sure if that’s what you were asking I was just trying to make it clear it is t just a replacement Slave that bolts to the bellhousing like the original. I hope to get to it very soon and I till post pics as best as I can.

5abivt

Only other update is I was killing time and found a song I liked so I made another short video. I believe I’ve posted all of the pics here already and the vids but I chose all the recent ones that weren’t in my first video. Please check it out !! Can’t wait until spring when I can start making actual vlogs and new videos and pics !