Tilton Hydraulic Bearing Issue

Jim Zagg · #1 (**permalink**) 02-26-2012, 05:17 AM

I have a 390 FE with a stock cast iron bellhousing and a Hays Long style clutch and a Tilton 600 series hydraulic bearing. 61-618 base and 61-604 bearing for a 1 1/16-10 Toploader 4 speed. Here is my problem. Clutch finger to bellhousing dimension is 2.735" and transmission to front of bearing dimension is 3.110. I need a transmission dimension of 2.600". I sent an email last week to tilton and no answer yet. The instruction sheet says the bearing base combo can go down to 2.770". I'm thinking it has the wrong piston in it but it still won't be short enough. I sent an email to RAM and they say I can use their bearing number 78136 and turn down the front bearing retainer to 1.370" and it will fit. Any of you guys have any ideas?

blykins · #2 (**permalink**) 02-26-2012, 05:42 AM

No room for a clutch fork?

Jim Zagg · #3 (**permalink**) 02-26-2012, 06:47 AM

Tried that. Clutch fork hits the frame rail where the frame tapers under the tunnel. Tried to change the angle of the pivot and change the length too! Gotta use internal bearing. I want to put the car togetrher and drive it this year!!!

Tom Cimino · #4 (**permalink**) 02-26-2012, 08:35 AM

I had a similar problem with the same setup, except with a 302/stock cast bellhousing. I went with a diaphram pressure plate and removed the "big bearing" adapter from the throwout bearing. You shouldn't need it with the 1 1/16" input toploader. By removing the adapter, you will gain .090". By doing these two things I gained enough clearance for it to work.

By the way, that's a neat tool you have for measuring. I've never seen that before.

I'm back again.

I was just thinking and realized that with my big block upgrade (Still in progress) the Tilton slave cylinder would not work, even with a diaphram pressure plate. I have a Tremec with the short input shaft. My solution was to re-install the longer shaft and go with a Quick time bell. That gives me another 5/8".

Rick Parker · #5 (**permalink**) 02-26-2012, 11:55 AM

Contact Hays, they often have different release fingers that can be substituted and will change the static verticle height of the surface that the bearing rides in. If Hays plays dumb, then contact Mcleod, parts will interchange. However, be sure the bearing you are using has enough travel for complete release of the pressure plate being used. Many times plates have different release points.

Jim Zagg · #6 (**permalink**) 02-26-2012, 09:03 PM

Well I solved my problem. After staring at the bearing and the base I held the bearing in my hands and squeezed the piston all the way back and it bottomed the seal in the bore. That got me down to 2.790 length. Then I spent 3 hours machining the base on my lathe removing material so the bearing would thread on further. Now I have an assembled length of 2.585". I decided to try my Centerforce clutch instead of the Hays thinking the pedal pressure would be less and less force on the base that I lightened by removing material. I hope it works. If you look close at the picture you can see the clearence.

lal Naja · #7 (**permalink**) 02-26-2012, 09:36 PM

Looks like you did a great job with the modification.

When I was doing mine, I found out that the type of throw-out bearing can be one of two types. One that needs a small space between it and the clutch fingers and this is for a centered bearing.

The other is for a self-centering/self-aligning bearing and needs a little pre-load on the clutch fingers.

The self centering/pre-load bearing fails in not installed with the pre-load.

Arthur