Any 42RH or trans experts? Question on frictions and steels

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roadrunninMark

roadrunninMark

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I am rebuilding a 94 42RH trans. It is all built except the O/D unit. I am using the ATSG manual as a reference. I've figured out that I have the "first design" level. According to the manual the steels I need for the direct/OD and O/D clutch packs should approximately be .070 thick. My mic puts them at about .065, which is close. I ASSUME I should buy the .070 thick steels? RockAuto lists many different thicknesses that are close to that (.068, .069, .070 for example). Should I order the exact size, .070 even though mine measure about .065 (wear? mic inaccuracy?, will that much difference matter?)?

Second question pertains to the friction plates. I am not seeing a thickness in the manual on which frictions to order. Mine measure .063 for direct/OD and .081 on the OD clutch pack. I ASSUME there has been wear since new, but should they all be the same thickness?

My clutch pack numbers are as follows:

direct/OD pack: 6 friction, 5 steels
OD pack: 4 friction, 3 steels.

I just need help figuring which thickness and brand I should get. I would like better power holding then stock (for about a 400hp 318, 3.55 gear, mostly street cruiser). I used mancini kit for the main trans rebuild with some SMR upgrades.

Thank you for the help.
 
roadrunninMark said:
I am rebuilding a 94 42RH trans. It is all built except the O/D unit. I am using the ATSG manual as a reference. I've figured out that I have the "first design" level. According to the manual the steels I need for the direct/OD and O/D clutch packs should approximately be .070 thick. My mic puts them at about .065, which is close. I ASSUME I should buy the .070 thick steels? RockAuto lists many different thicknesses that are close to that (.068, .069, .070 for example). Should I order the exact size, .070 even though mine measure about .065 (wear? mic inaccuracy?, will that much difference matter?)?

Second question pertains to the friction plates. I am not seeing a thickness in the manual on which frictions to order. Mine measure .063 for direct/OD and .081 on the OD clutch pack. I ASSUME there has been wear since new, but should they all be the same thickness?

My clutch pack numbers are as follows:

direct/OD pack: 6 friction, 5 steels
OD pack: 4 friction, 3 steels.

I just need help figuring which thickness and brand I should get. I would like better power holding then stock (for about a 400hp 318, 3.55 gear, mostly street cruiser). I used mancini kit for the main trans rebuild with some SMR upgrades.

Thank you for the help.
Click to expand...
I'm not sure of the numerical answer to your questions, but the answer may by in this book, by Carl Munroe:

https://www.amazon.com/dp/B004XDM44K/?tag=joeychgo-20
 
This video shows the 42rh being rebuild ....the OD section begins at 14:15 into the video

 
roadrunninMark said:
I am rebuilding a 94 42RH trans. It is all built except the O/D unit. I am using the ATSG manual as a reference. I've figured out that I have the "first design" level. According to the manual the steels I need for the direct/OD and O/D clutch packs should approximately be .070 thick. My mic puts them at about .065, which is close. I ASSUME I should buy the .070 thick steels? RockAuto lists many different thicknesses that are close to that (.068, .069, .070 for example). Should I order the exact size, .070 even though mine measure about .065 (wear? mic inaccuracy?, will that much difference matter?)?

Second question pertains to the friction plates. I am not seeing a thickness in the manual on which frictions to order. Mine measure .063 for direct/OD and .081 on the OD clutch pack. I ASSUME there has been wear since new, but should they all be the same thickness?

My clutch pack numbers are as follows:

direct/OD pack: 6 friction, 5 steels
OD pack: 4 friction, 3 steels.

I just need help figuring which thickness and brand I should get. I would like better power holding then stock (for about a 400hp 318, 3.55 gear, mostly street cruiser). I used mancini kit for the main trans rebuild with some SMR upgrades.

Thank you for the help.
Click to expand...
According to the parts book I've got in front of me the plates measure as follows:
Overdrive Direct friction: .062
Overdrive Direct Steel : .068

Overdrive Friction(waved plate): .090
Overdrive Steel: .068

I can't say for sure, but the catalog I've got does not list any plates other than the factory stock ones for the OD section. There might be a performance plate out there though. The factory plates will be Raybestos.
Get the frictions from a transmission parts supplier, as this is what they do. If you've got a Transtar outlet near you, go to them, or check with W.I.T. (Google these outlets).
 
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Thanks Lou, that is exactly the info I needed. I sent you a PM on Moparts, please disregard.

Last question: Can I change my OD/Direct Pressure Plate to the "2nd Design" (which is thinner) and increase the number of friction and steels to be 8/7 (versus 6/5)? This would have me use .055 steels, not sure which frictions I would use.

THANKS!
 
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