62 Impala progress update.

yellow wagon

Well Known Member
Supporting Member 2
just cross reference the part # for the throwout bearing that you have. Should be able to find a length once you look that up. I used the Centerforce throwout bearing with the Centerforce dual friction clutch and couldn't be happier
 

tripower

Well Known Member
Supporting Member 2
just cross reference the part # for the throwout bearing that you have. Should be able to find a length once you look that up. I used the Centerforce throwout bearing with the Centerforce dual friction clutch and couldn't be happier
Like Jason mentioned I used the exact same components as him and all is well...:deal
 

Kdurgin

Well Known Member
Here is a picture of my clutch mounted on the 14 pound nodular iron flywheel. I was concerned the light flywheel might affect the car on take off but it seems to be fine. Also is a picture of the throw fork.

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Kdurgin

Well Known Member
Kevin, Verify that you have the correct throwout bearing installed. The 1 7/8" long bearing is used with the diaphragm style pressure plate and the 1 1/4" long bearing is used with the 3 finger Borg and Beck style pressure plate. I just went through this hard pedal, hard to adjust, etc. with a friend of mine that had clutch problems for years. Found the short bearing installed on his diaphragm clutch. Put in the long bearing and all his good. BTW, This clutch was so screwed up that he broke two Z bars. Leo

Looking through my receipts, I have a RAM-488 release bearing which would be the 1.27 inch long one. The 489 is their 1.75 long one. IF I switch the release bearing to the long one, should I run a pivot ball the same length as the one I took out of a 64 stock clutch setup? It will kind of suck pulling that Tremec out after a mile to mess around with the bearing. I am going to pop off the clutch fork boot tomorrow and see if I can positively verify I have the short one in there and try and see how long the pivot ball stud is too. I think I have 3 different length pivot ball studs on the shelf.
 

DonSSDD

Well Known Member
Supporting Member 2
I think you have the correct TO bearing. The pivot ball stud is likely OK too, they do not change the geometry of the z bar or shaft, I think they have different sizes of threads in the block, and the balls and length may be different to fit different sizes of z bars. If you disconnect the rods from it, does the z bar move freely without binding? If so, its likely good too. If the biggest problem you have is the amount of strength it takes to use the pedal, it may just be that's the way the clutch you bought acts. Do you know anyone else that has the same clutch?

Don
 

Kdurgin

Well Known Member
Well here is the update: I pulled the Tremec out today and removed the throwout bearing. It was the short 1.25" one, RAM part number 488. I measured the length of the one out of the '64 I parted and it was 1.8" long. I went and bought an SKF 1086-SA bearing which is the 1.8" long 1.375I.D. bearing. I also verified my throw fork pivot ball installed inside the bell housing was the same length as the '64 so I left it in. I re-assembled everything and what a difference. The tranny goes easily into any 1st gear or reverse with no signs of grinding at all. Pedal effort is reduced quite a bit and is now as I would expect with a performance clutch. I'm thinking it is due to the different geometry between the throw fork and pivot ball and the longer bearing also starts the z-bar out at a different spot rotationally which affects the arm geometry on that as well. The post about breaking z-bars really got me thinking about the geometry and that is why I pulled it today. I hate doing rework on these type things but it was worth it today. I'll post pictures which include looking up at my floor tunnel so anyone thinking about a Tremec TKO swap can see what it ended up looking like.

Here is the culprit, the short bearing versus the old. Both pivot balls are the same length.

Tremecthrowoutbearingswapday007.jpg


Before with short bearing:

Tremecthrowoutbearingswapday001.jpg


After with longer bearing:

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Showing use of stock crossmember with TKO 600 tranny:reverse switch with sealed connector and speedo cable adapter and cable installed.

Tremecthrowoutbearingswapday005.jpg

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This shows the new shift hole for the TKOtranny in my raised tunnel.

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Thanks for the help on this one.
 

62impala409

 
Supporting Member 1
Glad the clutch worked out Kevin. We also stayed with the short ball stud with the long bearing. No one seems to know about the difference in bearing length or their importance. The pictures are an excellent source of info. Thanks, Leo
 

DonSSDD

Well Known Member
Supporting Member 2
Great that it worked out so well. I think the short versus long TOB has to do with the clutch and pressure plate you use and or the fork. The bells are all the same length front to back.
Show Cars says:
Clutch Release (Throwout) Bearings 05.090

4848 56-70 long clutch release bearing with diaphragm clutch-straight fingers... Ea. $20.50
4849 56-70 short clutch release bearing with coil spring clutch and 64 & up diaphragm clutch with bent fingers... Ea. $19.80

7752 Centerforce self aligning short throwout bearing... Ea. $41.00

The forks look similar, except they have different methods for the rod from the z bar to the fork.

Don
 
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