Which clutch for Toploader to Tremec swap

[patrickt]

Did he have any preference on throw out bearings?

[blykins]

Originally Posted by Grubby

Jim - good advice.

Doug said it was certainly a Center Force clutch. He said to simply call Summit and order a clutch disc that is 11", 1 1/8"-26 and it would fit. He also gave me some other tips on doing the trans swap. Super nice guy, just like the rest of the gang in CT.

I ordered a new Center Force clutch disc today.

John

Did your pressure plate have the counterweights on it?

[blykins]

If it has the counterweights, then it has been modified by Centerforce. LUK makes standard stock replacement stuff and they sell to Centerforce, who in turns adds their counterweights. I never put 2 and 2 together when you were telling me it was a diaphragm clutch.

[Grubby]

I did not ask about throw out bearings. My car only has 800 miles on it and I see no need in replacing it.

I can't tell if my pressure plate had the weights or not. ERA does suggest removing them, so they would have been removed before install.

John

[blykins]

Which disc did you order? Is it a "dual friction" disc?

Keep in mind that a Centerforce plate with no counterweights is just a stock replacement plate, so you really need to go sticky on the disc to hold the power.

[patrickt]

I don't believe you can order the DF disc separately. It comes in a matched package with the PP. Grubby, what other tips did Doug offer on the swap?

[Grubby]

Doug suggested the DF pressure plate. I also discovered it is not available separate, so I ordered a CenterForce II.

Drive shaft needs shortened 13/16", use 72-73 Camaro M/T trans mount, trim off part of the back of the TKO case for frame clearance (picture in manual), and raise the trans mount pad that attaches to the frame. Possible to patch Toploader shifter hole with aluminum patch or drill the rivets and replace the entire top of the aluminum tunnel.

My initial measurements indicate the TKO shifter stub will come up through the very front of the Toploader hole. The shifter will need to be moved back about 1.6" to be centered in the existing hole. I may make up an offset plate for my shift handle to move it to the center of the old hole. It is not clear if the stub is low enough to allow the boot to cover and hide an adapter.

As part of this change I am going from 3.07 rear to 3.54 rear. Doug said call back for assistance with that piece. Some of the Jag parts can be tricky.

John

[Excaliber]

Personally, I would stay with the 3.07. I have the typical 3.31 and I'd prefer a higher (lower numerically) gear than that.

The TKO-600 has a fairly low 1st and 2nd gear ratio already. Going to low (and 3.5 is TO low) will add to additional traction issues.

Consider this, many many "Cobras" run a 12 second quarter, don't care how big your motor is, how much h.p./torque you got, your going to be in the 12's. Why? TRACTION, you can't get it without serious tires. BUT, a higher gear ratio is a BIG step toward getting a handle on it. Most Cobra's are easily in the low 11's, dare I say even the 10's, IF they could actually get out of the hole from anything greater than idle speed because of wheel spin!

By the way, a .6 or a .8 over drive on that TKO?

[patrickt]

I have the 3.54 -- it's perfect. Here are a couple of shots of my TKO and how it lines up with the shift hole in your tunnel. I'm using the spacer between TKO and the bellhousing. You might also need the little aluminum block spacer on your slave as well.

[Excaliber]

Patrick, I think your setup utilizes a spacer between the trans and bell housing? That moves the trans back "just enough". I went without a spacer (don't really like them) and had to modify the tunnel hole position as a result.

3.54 rear gear, great for tire smoke, drifting, parades and like that. Without serious traction it will totally suck at the drag strip. A 2 second 60 foot time would be "good" (and that is some kind of slow)! Nope, wishing I had a 3.07 rear gear with that TKO I got!

[blykins]

Originally Posted by Grubby

Doug suggested the DF pressure plate. I also discovered it is not available separate, so I ordered a CenterForce II.

Drive shaft needs shortened 13/16", use 72-73 Camaro M/T trans mount, trim off part of the back of the TKO case for frame clearance (picture in manual), and raise the trans mount pad that attaches to the frame. Possible to patch Toploader shifter hole with aluminum patch or drill the rivets and replace the entire top of the aluminum tunnel.

My initial measurements indicate the TKO shifter stub will come up through the very front of the Toploader hole. The shifter will need to be moved back about 1.6" to be centered in the existing hole. I may make up an offset plate for my shift handle to move it to the center of the old hole. It is not clear if the stub is low enough to allow the boot to cover and hide an adapter.

As part of this change I am going from 3.07 rear to 3.54 rear. Doug said call back for assistance with that piece. Some of the Jag parts can be tricky.

John

If you don't want to cut up the transmission tunnel, there are shifters available that will offset it the correct amount. They are also an upgrade from the factory Tremec shifter, available with adjustable stops, short throws, and spring loaded bases.

[blykins]

Ernie, you didn't need to trim the rear piece off of your tailhousing did you? Is it because it's a newer frame revision maybe?

[patrickt]

Originally Posted by Grubby

I did not ask about throw out bearings. My car only has 800 miles on it and I see no need in replacing it.

John, the reason I asked is that some of the Toploader TOBs will not work with the TKO. Here's where Lykins comes in handy. I believe only the small input TL's TOB is compatible with the TKO. Is that correct, Brent? And what's the deal with the zerk fitting on the McLeod TOB?

[Excaliber]

In my case, I did not need to trim any metal off the trans anywhere. I also used the same trans mount that was on my top loader.

[blykins]

I wasn't handy until now?

Yes, the OD of a small input Toploader bearing retainer and a TKO 500/600 bearing retainer are the same so you can use the same TOB.

[patrickt]

Originally Posted by blykins

I wasn't handy until now?

Yes, the OD of a small input Toploader bearing retainer and a TKO 500/600 bearing retainer are the same so you can use the same TOB.

Yes, you're always handy, but I was looking at a McLeod TOB the other day and was surprised to see that it had a zerk fitting on the side. Is that just a gimmick?

[Grubby]

I plan to use the spacer between the trans and bell. It will put the shifter in a closer to original location. Doug at ERA said the piece on the back of the trans needed trimmed. I did that per the book. I suspect it does not need trimmed if you do not use the spacer.

Brent - I may call about the offset shifter. I need to get the tunnel in and see how things look. I may just offset the shift handle with plate steel, I may patch the tunnel and put the hole in the typical ERA location. I have not decided yet.

Excaliber - My car is difficult in city traffic. It needs more gear. On the open road it is OK. My last ERA had 3.54 gears with a Tremec and I was very satisfied. Doug (at ERA) ask me which gear I planned to run and suggested the 3.54, but I had already made up my mind. He said the car would be doggy with the 3.07 - and it is.

We all drive our cars differently and want different things from them. I already have a complete Jag 3rd member ready to go, the 3.07 unit will be for sale soon if you want to change yours out. It was built by ERA.

This has been a good thread.

John

[Jim Holden]

John:

I used a 3:08 rear in my second 428cj ERA427SC with what ws then called a Doug Nash 4+1 (now Richmond) where 5th is 1:1. I thought that combination was great. Numerically, 4th gear (1.24 ratio) worked out to be approximately equivilent to a Top Loader four speed with 3:54 rear (See: http://www.richmondgear.com/07pdfs/RG23.pdf)

If I ever build another big block car with that rear gear ratio, I would use the Richmond 5 speed (where 5th is 1:1)

Jim

[patrickt]

I had mine out today for a short while, but it was a little chilly. The 3.54 with the Tremec, I think, is absolutely perfect -- it might not be perfect for the drag strip, but it allows you to go slowly in first gear, which is nice. Now it can be a tricky call for the fifth gear, but I went with the .64 -- around here highway speeds are 70 and above and my engine is comfortable at just over 2000RPM. One of my absolute favorite things to do is to take her out on the interstates towards the mountains and just piddle along at 70mph at just a hair over 2000RPM. There's more wind noise than there is side pipe noise, and it's just delightful. It's a cruise-only gear, though. Certainly not for road racing.

[Excaliber]

Yeah, with a .6 OD, a 3.07-8 would be to high on the highway, 3.5 is a better call. Cam profile, flywheel weight, torque, driver habits, cruise rpm at a reasonable mph (70 is reasonable), trans OD ratio, all these things come into play.

I don't drag much, maybe a couple of times a year is all, so I'm primarily concerned with driving around town wheel spin, which is to much for my taste. That is tempting to consider a swap to a higher rear gear ratio. My main problem there is I don't want to do all the work! OK, I'll buy it for a good price, now, who's coming over to put it in? Pizza is on me...

I had mine out as well, ran a few errands, about 50 degrees here, not to bad. That new heater works well!