FJ40 rear output shaft bearing replacement (1 Viewer)

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Hi all I’m new to LC community and need some advice. I bought this 1973 FJ 40 a few months ago and since then it’s had a bad vibration from the driveline. It’s a small block Chevy conversion with a 700r4 AT. It was a good restoration from what I can tell and Everything seems to have been done correctly. I pulled the rear driveline off down to the output shaft bearing. There seems to be some play in the bearing. I’m assuming there shouldn’t be any play there? It looks like the bearing is pressed in and I’m wondering if i have to remove the TCase to replace it or if it can be removed in place? I’ve seen all the threads I can find on driveline vibrations and have narrowed it down to this bearing.
 

reddingcruiser

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The short answer - you have to remove the t-case. The bearing is pressed onto the main shaft, the race sits in the case and preload is set with shims under the speedo housing/rear cover. If you are tempted to try and shim the bearing to reduce the play I would encourage you not to do that, since you'll never know what damage has occurred to either the bearing or race without taking it apart. Just my opinion.
 
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The short answer - you have to remove the t-case. The bearing is pressed onto the main shaft, the race sits in the case and preload is set with shims under the speedo housing/rear cover. If you are tempted to try and shim the bearing to reduce the play I would encourage you not to do that, since you'll never know what damage has occurred to either the bearing or race without taking it apart. Just my opinion.
 
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That’s what I was afraid of. Once the Tcase is out and the front drive housing is off and the appropriate bearing and hardware is off does the output shaft slide forward so I can knock the rear shaft bearing out? I can’t find anything in my manual or online anywhere how to disassemble this thing!
 

reddingcruiser

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Do you have a Toyota FSM for your FJ40? IMHO, everyone with an FJ40 should own a FSM and Haynes Manual, and they come up from time to time in the classified. However, I know someone on here on 'mud has a link to digital versions, and they may also be available in the FAQ section.

You are partly correct, the main shaft and rear bearing presses off through the front of the t-case. Disassembly is pretty straight forward. Reassembly, including clearances and preloads are pretty technical and require a FSM or similar to put the t-case back together properly.
 

65swb45

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Agree with @reddingcruiser on all counts. The very fact that you are having to look into something you previously thought had been done well is reason enough to not just try and re-shim, but do a tear down.
 
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I only have the the chilton’s manual. I’ll have to look for the fms. So how are people pressing out the shaft and bearing? Can a dead blow hammer be used? I didn’t realize the bearing was actually pressed on to the shaft.
 
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Agree with @reddingcruiser on all counts. The very fact that you are having to look into something you previously thought had been done well is reason enough to not just try and re-shim, but do a tear down.
I’m not sure in this case but what I know about pressed bearings there shouldn’t be any play in this thing?
 

65swb45

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I’m not sure in this case but what I know about pressed bearings there shouldn’t be any play in this thing?

Correct. The FSM explains how to measure the preload on the bearings once you have shimed the race against the tapered roller bearing.

It’s a good time to consider a dual seal speedometer housing upgrade while you’re in there.
 
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Correct. The FSM explains how to measure the preload on the bearings once you have shimed the race against the tapered roller bearing.

It’s a good time to consider a dual seal speedometer housing upgrade while you’re in there.
The body and Tcase are about the only Items on this vehicle.
 
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Correct. The FSM explains how to measure the preload on the bearings once you have shimed the race against the tapered roller bearing.

It’s a good time to consider a dual seal speedometer housing upgrade while you’re in there.
When getting an FSM would it be the engine manual that would address the transfer case?
 
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Thanks Jon. I was hoping someone would chime in with those links.
Sadly that bearing doesn’t look like mine.
1907211
 
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I don’t understand how to set the preload. What is the scale they talk about attaching? Do you get the shims from the dealer?
 

reddingcruiser

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Preload is set with shims under the speedo housing. The scale is a pull scale (ala fish scale). Shims can come from Toyota, or some of the fine 'mud vendors here. I'm sure either Mark, Georg or Kurt can supply them. Essentially, the shims cause the speedo cover to 'squeeze' the two bearings on the main shaft by forcing the rear bearing race forward. Since the front bearing and race are trapped by the nose cone, pressure, or preload, is created. Start with no shims and work your way up until you get to the proper preload. The FSM tells you how to hook up the scale, be sure you are pulling smooth and steady and at 90º to the studs in the direction of rotation (If that makes sense). Everyone else can feel free to chime in.
 
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Preload is set with shims under the speedo housing. The scale is a pull scale (ala fish scale). Shims can come from Toyota, or some of the fine 'mud vendors here. I'm sure either Mark, Georg or Kurt can supply them. Essentially, the shims cause the speedo cover to 'squeeze' the two bearings on the main shaft by forcing the rear bearing race forward. Since the front bearing and race are trapped by the nose cone, pressure, or preload, is created. Start with no shims and work your way up until you get to the proper preload. The FSM tells you how to hook up the scale, be sure you are pulling smooth and steady and at 90º to the studs in the direction of rotation (If that makes sense). Everyone else can feel free to chime in.
 

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