Transmission Rattle (1 Viewer)

[RWBeringer4x4]

Hey All -

I have a 1975 FJ40/350SBC conversion - original 4 speed trans/t-case.

The last couple of times I had the truck out I have noticed a loud "rattling" coming from my transmission (I think). This tends to happen in the higher gears - most noticeable in 3rd and 4th, almost not noticeable at all in 1st and 2nd. It increases in speed under load, rattles obnoxiously when coasting. It sounds like there is literally a bolt jumping around in my bell housing, and I can feel whatever it is knocking around through the shifter. It still shifts perfectly smooth through all gears without hesitation. Any ideas?

1. A couple other things: I also have a bad throw-out bearing ("chugging" when I don't have the clutch in, goes away when I do).

2. The transfer-case will currently only shift between 2H and 4H, but will not shift into N or 4L. I have been hitting the linkage with PB blaster to try and loosen it up (if that's the issue) and trying to move the t-case stick around. Could this be part of the problem?

I don't remember this sound when I bought it 2 weeks ago

Any suggestions you might have would be greatly appreciated!

 

[RWBeringer4x4]

A little more info -

1. Seems to get worse (louder) as the engine/transmission warm up

I have been reading up on gear rollover, it's the only thing I can find described as sounding like "marbles rolling around your transmission" and it is apparently harmless, but I don't want to make any assumptions and blow up the FJ.

Any thoughts?

 

[RWBeringer4x4]

Another thought -

Physically feeling the rattle is very prominent through the gearshift lever, particularly in 4th gear - could this be something to do with the linkage itself?

I'm new to Land Cruisers, but do FJ40 transmissions use the same ball-shaped bushing/detent system most manual transmissions use to mount the shift linkage to the trasmission?

Could the rattle in 3rd and 4th be from a bad ball/bushing here? I would think that would rattle in ALL gears. Totally at a loss...

 

[69fj4069]

I would check the driveshafts and u-joints. I had a vibration like yours because the yokes on my driveshaft were not in line with each other.

 

[John Smith]

Have you checked the gear oil level in both the transmission and transfer case? If not, do so. I would then drain at least the transmission and see what has collected on the drain plug.

 

[RWBeringer4x4]

I would check the driveshafts and u-joints. I had a vibration like yours because the yokes on my driveshaft were not in line with each other.

I'll take a look - but this is more of a rattle and less a vibration - was yours a vibration through the whole truck or just the shifter? Mine literally sounds like a marble in a tin can, and it feels like it is rolling around the bottom of the shift linkage...

Have you checked the gear oil level in both the transmission and transfer case? If not, do so. I would then drain at least the transmission and see what has collected on the drain plug.

Transmission/Tcase are full - but I have not gotten around to draining them yet (just bought it). What would I be looking for to collect? chunks of metal?

 

[Fast Eddy]

1. A couple other things: I also have a bad throw-out bearing ("chugging" when I don't have the clutch in, goes away when I do).

Your throw-out bearing shouldn't be turning when the clutch is out. Do you have a clutch return spring? Probably needs adjusting. Not sure if that's your problem.

I'm pretty sure it has nothing to do with the linkage.

 

[RWBeringer4x4]

I'm pretty sure it has nothing to do with the linkage.

Thanks for the response Eddy,

Not clear on the last part - are you saying

1. The TOB has nothing to do with the rattle I'm hearing or

2. The linkage has nothing to do with the rattle I'm hearing

 

[John Smith]

I'll take a look - but this is more of a rattle and less a vibration - was yours a vibration through the whole truck or just the shifter? Mine literally sounds like a marble in a tin can, and it feels like it is rolling around the bottom of the shift linkage...



Transmission/Tcase are full - but I have not gotten around to draining them yet (just bought it). What would I be looking for to collect? chunks of metal?

Yes, you are looking for chunks of metal.

 

[kurtnkegger]

I had a slight rattle found to be coming from the transfer case shifter rather than the transmission. The rattle was from the shifter not being fully seated in the 2H position. After I moved the stick in to position the rattle stopped. Point being, if you are having trouble getting your transfer case to shift in to other modes, you might not be fully seated in the gearing you can achieve.

 

[Fast Eddy]

2. The linkage has nothing to do with the rattle I'm hearing

This. ^^^, although on 2nd thought the t-case linkage could rattle. You can reach up from underneath while you're adjusting the clutch and see how much play it has in it.

 

[RWBeringer4x4]

Point being, if you are having trouble getting your transfer case to shift in to other modes, you might not be fully seated in the gearing you can achieve.

If it is that obvious I will kick myself, but I'll also be thrilled. Since the T-case linkage mounts to the transmission it's possible I could be feeling the T-case rattle through my gearshift. Might have to go try that tonight.

You can reach up from underneath while you're adjusting the clutch and see how much play it has in it.

I can already tell you there's a ton of play - it will flex all the way over to the side of the hole in the transmission hump without actually moving to N or 4L.

 

[Splangy]

Sounds like a worn gear selector ring and arm(i forget what it's called) in the transfer case. I've seen them severly worn and cause loud rattling like you described. Although, the fact that you're hearing it more in higher gears may not make sense. Maybe it's just because it's spinning faster.

 

[RWBeringer4x4]

Sounds like a worn gear selector ring and arm(i forget what it's called) in the transfer case.

Not sure what part you're talking about, but since this is IN the T-case - does that mean dropping the trans/t-case to repair?

 

[Fast Eddy]

Not sure what part you're talking about, but since this is IN the T-case - does that mean dropping the trans/t-case to repair?

If that is the problem the solution is a t-case rebuild with some new parts. Yes, dropping the t-case. You could tell if it was this by putting some sideways pressure on the t-case level while it's happening. If it goes away, that's your problem. You may not be able to put pressure on it when it's in 2wd due to the 2-lo blocker. Assuming you have locking hubs, leave them unlocked, shift to 4wd and try the experiment.

 

[RWBeringer4x4]

Well, I'm hoping Kurtnkegger is right then! This damn T-case is becoming the first of many major PITA's I will undoubtedly come across.

 

[Splangy]

If that is the problem the solution is a t-case rebuild with some new parts. Yes, dropping the t-case. You could tell if it was this by putting some sideways pressure on the t-case level while it's happening. If it goes away, that's your problem. You may not be able to put pressure on it when it's in 2wd due to the 2-lo blocker. Assuming you have locking hubs, leave them unlocked, shift to 4wd and try the experiment.

I doubt that putting presssure on the TC shift lever would eliminate the rattle if it was the cause.

 

[Fast Eddy]

I doubt that putting presssure on the TC shift lever would eliminate the rattle if it was the cause.

Really? If it's the gear selector collar rattling against the shift fork it seems to me that mashing them together would eliminate the rattle temporarily.

 

[DSRTRDR]

I had a slight rattle found to be coming from the transfer case shifter rather than the transmission. The rattle was from the shifter not being fully seated in the 2H position. After I moved the stick in to position the rattle stopped. Point being, if you are having trouble getting your transfer case to shift in to other modes, you might not be fully seated in the gearing you can achieve.

I have had this happen

 

[RWBeringer4x4]

Thank you all for the responses! Looks like I have quite a few things to try this weekend. I'll report back with anything I am able to discover.