TOB shim thickness

[jbpellegrino]

I am in the middle of swapping the engine in my 06 Mustang. A new clutch kit is a part of that swap - the Exedy Mach 500. I have read through various posts here (mainly from Dep. of Boost) explaining shimming the TOB for the correct preload, and I have made my measurements and think I know what size shim I’ll need. I was looking for a second opinion before ordering and bolting things up.

From the bellhousing to the TOB face: 2 & 21/32”
(Pictures provided for reference, measurements taken more steadily…)


From engine/trans separator plate to “face” of pressure plate: 3 & 1/4”


From the “face” of the pressure plate to the clutch fingers: 5/32”


If my math and measurements are correct, it seems that I have 7/16” of preload currently and need to (ideally) find a 9/16” shim.

IIRC, DOB mentioned that up to a 1/4 of variance from the recommended 1” of preload is acceptable. It seems that the maximum travel of my TOB is 1 & 1/8”. Maybe a 1/2” shim is the way to go so I don’t max out the TOB?

Also don’t want to push the clutch line into the trans too far…

 

[Midlife Crises]

I think you have the right idea. Allowing for wiggle room I figure you have between 3/8 and 7/16” preload. A 3/8” thick spacer plate should allow it to work and not be at the end of its travel. A 1/2” thick spacer plate will work for sure but it’s a little more difficult to get the clutch hydraulic line attached.

 

[86GT351]

I am in the middle of swapping the engine in my 06 Mustang. A new clutch kit is a part of that swap - the Exedy Mach 500. I have read through various posts here (mainly from Dep. of Boost) explaining shimming the TOB for the correct preload, and I have made my measurements and think I know what size shim I’ll need. I was looking for a second opinion before ordering and bolting things up.

From the bellhousing to the TOB face: 2 & 21/32”
(Pictures provided for reference, measurements taken more steadily…)
View attachment 108972

From engine/trans separator plate to “face” of pressure plate: 3 & 1/4”
View attachment 108973

From the “face” of the pressure plate to the clutch fingers: 5/32”
View attachment 108974

If my math and measurements are correct, it seems that I have 7/16” of preload currently and need to (ideally) find a 9/16” shim.

IIRC, DOB mentioned that up to a 1/4 of variance from the recommended 1” of preload is acceptable. It seems that the maximum travel of my TOB is 1 & 1/8”. Maybe a 1/2” shim is the way to go so I don’t max out the TOB?

Also don’t want to push the clutch line into the trans too far…
View attachment 108975

I believe that is correct. Have you reached out to Exeddy?

 

[jbpellegrino]

Ordered a 3/8” shim. Clutch line should still be able to connect, maybe not the black locator bracket/clip… Will try to maybe seal off the area after the engine and transmission are lowered into the engine bay.

Overall preload should now be 0.8125”, a little over the low end acceptable preload of 0.75”

 

[JC SSP]

My GT is auto but I have to ask… does the stock GT or better yet the stock GT500 require and TB shims?

 

[ghunt81]

Are you doing a braided clutch line as part of your swap? If not I highly recommend it.

Also don't know if you already know it but bleeding the clutch with a vacuum bleeder is a must.

 

[Midlife Crises]

My GT is auto but I have to ask… does the stock GT or better yet the stock GT500 require and TB shims?

No idea if some do and some don’t need shims. My 2010 GT with a 3650 had no shims from the factory and shifted OK until I beat the synchros out of it. Went back together with a McLeod clutch, pressure plate, flywheel, throwout unit and a T56 magnum XL. I had to drop the tranny and add a 1/4” shim plate because it would nibble first gear going in from a stop.

 

[ledmircy]

My GT is auto but I have to ask… does the stock GT or better yet the stock GT500 require and TB shims?

stock GT typically doesn't need shims, but GT500 does.

 

[brasil]

... if I use a master cylinder from a 13 GT 500 - does it change something in connection with the OEM TOB ?
Askin because , they say the GT500 cylinder makes a little more " travel /higher volume "

So I am not sure, if I can use the GT500 cylinder "plug and play"

The braided clutch line with a bleeder, I already have ..

 

[jbpellegrino]

Are you doing a braided clutch line as part of your swap?

No - I wasn't able to get the clip off of the upper part of the clutch line near the firewall, underneath the master cylinder. The OEM heat wrap around the line looks to be in good condition and the only point of removal has a new o-ring (TOB line).

Also don't know if you already know it but bleeding the clutch with a vacuum bleeder is a must.

I will have to pick up a handheld vacuum bleeder from harbor freight - thanks! Was planning on bench bleeding the TOB and pumping the clutch till my leg gives up... then some more


Hays 82-116 Hydraulic Release Bearing Shim - 0.375" delivered today. Measured 10.0mm, or 0.39". This makes the overall preload 0.8275", not 0.8125". Better more preload than less in my case Unfortunately the locating lip/ring on the outside of the TOB mounting face will no longer keep everything concentric due to the shim being almost double the depth of the lip. Will have to eyeball it and feel around edges unless there's a better option...

 

[lwarrior1016]

No - I wasn't able to get the clip off of the upper part of the clutch line near the firewall, underneath the master cylinder. The OEM heat wrap around the line looks to be in good condition and the only point of removal has a new o-ring (TOB line).

I will have to pick up a handheld vacuum bleeder from harbor freight - thanks! Was planning on bench bleeding the TOB and pumping the clutch till my leg gives up... then some more


Hays 82-116 Hydraulic Release Bearing Shim - 0.375" delivered today. Measured 10.0mm, or 0.39". This makes the overall preload 0.8275", not 0.8125". Better more preload than less in my case Unfortunately the locating lip/ring on the outside of the TOB mounting face will no longer keep everything concentric due to the shim being almost double the depth of the lip. Will have to eyeball it and feel around edges unless there's a better option...


View attachment 109148

Just eyeball it and center it the best you can. Don’t forget, you now need longer bolts.

 

[jbpellegrino]

Shim installed, transmission attached to engine, engine and transmission back in the car. To anyone who finds they need to shim their TOB and did NOT remove the clutch line from the car, I now would highly recommend doing so…

It seems like any shim at all pushes the TOB line too far into the bell housing for the metal clip to snap into the plastic clutch line connector after it’s assembled. I was forced to remove the engine and trans from the car, separate them, remove the TOB, and reinstall it with the clutch line already connected to the TOB (C clip in place, too… that’s why I had to spend the rest of my afternoon anyways )