Transmission Rattle

[RWBeringer4x4]

Ok upon further investigation: the rattle seems more speed related than gear related. I did make sure the t case was firmly seated in 2H, rattle persists in 4H as well. Starts at 30+ mph, and actually gets much worse if I put the truck in neutral at that speed and let it "coast." If you put the 40 in neutral Doing 35mph and leave your hand on the shifter, that is when it feels like something is bouncing around in the transmission.

Gonna keep digging into it some more- any new thoughts based on that info? It's still damn fun to drive though

 

[simpson110]

I am having the same exact issue with my cruiser. It will only make the noise when the driveline is under no load at all. As far as I can tell it must be coming from the transmission. I have an Orion t-case that is only 2 years old and the transmission has had little to no work done to it. To me it sounds like extreme gear chatter, where there is enough wear on the gears to let them bounce back and forth off one another under no load. I try not to coast to often because I hate the sound and I know it can't be good, but this winter I will be rebuilding the tranny anyway so hopefully it holds out until then.

 

[69fj4069]

Did you check out the driveshaft. Because this sounds like almost exactly the problem I was having when my yokes were out of alignment.

 

[Pighead]

I have had this happen

Ditto. Next time you hear the rattle, Put your hand on the sticks, one at a time, see if you can make the sound go away. Putting bungees around my triple-sticks really cuts down on the rattles.

 

[RWBeringer4x4]

Did you check out the driveshaft. Because this sounds like almost exactly the problem I was having when my yokes were out of alignment.

69fj: to be completely honest, I have no idea what I'm looking for. I can confirm that the drive shaft is, in fact attached to the truck, but beyond that, I'm not really sure what I'm looking for. It is very possible, with the V8 adaptation, that it may not be aligned correctly, but I'm not sure what to look for.

To me it sounds like extreme gear chatter, where there is enough wear on the gears to let them bounce back and forth off one another under no load. I try not to coast to often because I hate the sound and I know it can't be good, but this winter I will be rebuilding the tranny anyway so hopefully it holds out until then.

simpson - this sounds about right - but I am REALLY hoping you're wrong in the reasoning! I'm having too much fun driving it to drop the transmission so soon

 

[RWBeringer4x4]

Ditto. Next time you hear the rattle, Put your hand on the sticks, one at a time, see if you can make the sound go away. Putting bungees around my triple-sticks really cuts down on the rattles.

I did try this - wasn't able to stop the rattle. All the gears seem to be seating nicely, and it shifts like butter through all the gears. What I did notice in doing this though, is that I "feel" the rattle way more through the transmission shifter than the transfer case shifter.

I'm going to be ripping the trans tunnel out soon, hopefully, to check out my xfer linkage, and hopefully get the the bottom of the "no neutral or 4 low" issue. while I'm in there I might see what I can find regarding the trans as well.

 

[simpson110]

I have not checked taken my driveshaft out since I put the Orion transfer case in, but that does not mean its not the driveshaft. The u joints could be on their way out, I do grease any grease able fitting pretty often but they do still wear. I'll check out my drive shaft some time tonight and check back.

 

[RWBeringer4x4]

For me - (the uninitiated) how can you tell if the yokes are straight or if the U joints are going? I'm not even sure what to look for, but that is the exact reason I bought this thing, to learn! If you guys have pictures or sagely advice, feel free to chime in.

 

[Fast Eddy]

Do a search on "driveshaft alignment" and you will find pictures. I find that google searches with "site:ih8mud.com" work better than forum searches and you can click on "images".

google images: driveshaft alignment site:ih8mud.com

 

[RWBeringer4x4]

Thanks! I'll check it out!

 

[simpson110]

Well I checked my rear driveshaft, and the yokes are aligned properly. But I did seem to notice(well thought I noticed) a small amount of play in my rear pinion. I doesn't seem like the sound is coming from there but it is possible. My rear end was rebuilt 3 years ago but I do have a SOA conversion with a SBC and blocks, so I wouldn't be surprised if the bearing doesn't have the greatest life span. This winter I will be adding an anti wrap bar so that should eliminate any further issues.

So RWBeringer4x4 check to see if you have any play in your rear pinion, and we may have found the issue.

 

[RWBeringer4x4]

I will check it out tomorrow and report back, I'll try to include some pictures as well. Although I agree just by the "feel" of the rattle I would be (pleasantly) surprised if this is it! Stranger things have happened.

 

[RWBeringer4x4]

Ok checked out the drive shaft. Checked for play in the u joints and pinion, seemed solid. Drive shaft yokes seem aligned to me, picture attached, take a look.

 

[Fast Eddy]

Yup. Looks correctly aligned.

 

[RWBeringer4x4]

Glad you could tell, picture ended up way blurrier off the phone. So I guess that rules that out!

 

[RWBeringer4x4]

Back to Square 1

Ok so here's what we know so far:

1. "rattle" sounds like a bolt in a can, shows up at speeds of 30+ MPH in 3rd and 4th gear.

2. When slowing down or taking the 40 out of gear, rattle continues, and does not stop until the truck comes to a complete stop. It then wont happen again until I go back past 30MPH

3. Driveshaft yokes are aligned - very little rotational play in rear driveshaft, no lateral play whatsoever.

4. I can feel it through the transmission shift lever, but not through the T-case lever. Putting pressure on either lever does not change the rattle

Possibilities I still haven't eliminated:

1. Simpson's "severe gear chatter" theory

2. Could drain the transmission and look for metal, plus see if fresh gear oil helps.

3. The possibility that I have a loose flywheel bolt in my bell housing or something.

Gonna be heading out of town for a few days after tomorrow, but hopefully I'll be able to get the tranny hump sometime in the near future and dig a little deeper. Thank you to everyone who has chimed in so far, learning a lot just by eliminating all these possibilities.

 

[Pighead]

3. The possibility that I have a loose flywheel bolt in my bell housing or something.

I had some loose flywheel bolts once...only heard/felt the noise on sudden deceleration.

 

[1Fine40]

I had some loose flywheel bolts once...only heard/felt the noise on sudden deceleration.

Can I say "me too!" ?? I pulled the flywheel cover pan and out fell two bolts!

Cheers!

 

[RWBeringer4x4]

Shift Fork

Another thought - Looking at a diagram of the 4 speed transmission, it appears that there on shift fork for 1st and 2nd gear, and a second shift fork for 3rd and 4th gear. I get a good amount of driveline vibration in 3rd and 4th gear, and this is where the rattle occurs - could this be an issue with a bad mate or a bearing somehow associated with the shift fork? Has anyone ever had something like that happen? Is there something associated with the 3rd and 4th gear shift fork that would continue to spin after I engage the clutch? this would explain why I continue to feel the rattle after I disengage the gear.

Thoughts?

 

[DSRTRDR]

so, does it shift into 4L now ?