FJ62 Transfer Case Companion Flange Preload

Content may include affiliate links. Please see terms for details.

Joined
Sep 1, 2021
Messages
579
Location
Summerland BC
Hi.



I took my Rebuilt A440F transfer case, and put it on my H55F, the swap went well (I hope), but I am confused about the preload and the FSM doesn’t specify well.


What/how do you preload the front AND rear companion flange stake nuts? The FMS says that the nut must be torqued to 94-FT pounds- that seems really high!

But more over, after you torque it to 94 FT pounds, it says to preload check at 6.1 - 10.4 In.-lb or 0.7 - 1.2 Nm


I don’t understand….. I really don’t want to wreck my transfer case…… how can there be a torque spec AND a preload??????

1042CE28-F28C-44FB-9C2A-9D3DB243FBD4.jpeg


ED04CEDA-F9F7-4D99-8839-A1B25407238E.jpeg


76791183-8570-4ED6-8DAC-72FD32D5CBBA.png
 

cruisermatt

Un-manufacturable
Supporting Vendor
SILVER Star
Joined
Jul 22, 2012
Messages
12,494
Location
Winter Park, Florida
Website
www.facebook.com
It's simple. The output flange doesn't effect the bearing preload. The shim/s under the rear output bearing race do.
 
Joined
Sep 1, 2021
Messages
579
Location
Summerland BC
It's simple. The output flange doesn't effect the bearing preload. The shim/s under the rear output bearing race do.
Okay…. I still don’t understand.


Do I just torque down the nut to 94 Ft pounds and forget about it? I never changed the bearings or shims.
 
Joined
Dec 22, 2015
Messages
1,900
Location
Whitefish/Bozeman, MT
You'll need a torque meter or tiny, beam style torque wrench to check the preload. Basically you're adjusting how much static friction there is in the output shaft bearing assembly, or in other words how tightly the tapered roller bearings are pressed together. Too tight, and they'll get hot and wear out. Too loose, and there will be play and they'll wear out.
The basic procedure is this: assemble the transfer, torque the bearing retainer bolts, then use the torque meter to see how much torque it takes to rotate the output flange. If it is less than spec, you need an extra shim. If it is more than spec, you need to remove a shim. If you haven't replaced the bearings or shims then it is probably fine as-is.
Here's the setup for reference (way over spec here):
IMG_0418.jpeg
 

cruisermatt

Un-manufacturable
Supporting Vendor
SILVER Star
Joined
Jul 22, 2012
Messages
12,494
Location
Winter Park, Florida
Website
www.facebook.com
If it was correct before you shouldn’t have to adjust the shim stack.
 
Joined
Sep 1, 2021
Messages
579
Location
Summerland BC
You'll need a torque meter or tiny, beam style torque wrench to check the preload. Basically you're adjusting how much static friction there is in the output shaft bearing assembly, or in other words how tightly the tapered roller bearings are pressed together. Too tight, and they'll get hot and wear out. Too loose, and there will be play and they'll wear out.
The basic procedure is this: assemble the transfer, torque the bearing retainer bolts, then use the torque meter to see how much torque it takes to rotate the output flange. If it is less than spec, you need an extra shim. If it is more than spec, you need to remove a shim. If you haven't replaced the bearings or shims then it is probably fine as-is.
Here's the setup for reference (way over spec here):
View attachment 3230660

Thanks this makes sense.
 
Joined
Sep 1, 2021
Messages
579
Location
Summerland BC
If it was correct before you shouldn’t have to adjust the shim stack.
Yes. You are right. But I’m going to check anyways because the guy who I had rebuild it already made a few mistakes.
 
Joined
Dec 22, 2015
Messages
1,900
Location
Whitefish/Bozeman, MT
One other thing I just noticed: in the manual posted above it says to fully torque the stake nut on the companion flange before checking preload, but in the manual I used when I rebuilt my transfer (RM183E) it says to temporarily install the stake nut without the companion flange to check preload before final assembly. I don't think there are any significant differences between the 62 and 70 series transfer cases, so I would hazard a guess that it can be done either way.
 

Attachments

  • Transfer_output_preload.pdf
    162 KB · Views: 5

Users who are viewing this thread

Top Bottom