TH 350 rattle

Well I've done a search here and found little on topic. Admittedly, I'm not a tranny guy. Here's my head scratcher...

-slight rattle 1st and 2nd gear
-rattle increases a little in 3rd
-after you really get into it at highway speed, rattle gets pretty bad
-shifts fine, no slipping
-if I slip it into N while driving, rattle stops
-i drove with the floorboard hump off and with a stethoscope found the noise to be coming mainly from the passenger side of center- close to the bell housing (not on the bell housing)


I wouldn't think this would be a vacuum issue since it shifts fine. My best guess is some type of worn gearing. I've never torn apart a TH 350. I'm just seeking some direction before I yank this thing out and dive into it.

Any tranny guys have any ideas? Thanks in advance.

 

maybe loose torque converter bolts or cracks in the flexplate.

 

Where is your timing set at .Just another possibility .

 

bump for the morning crew.

Thanks fellas

 

This would be the first place I'd look. The only other thing I can think of in a 350 that might rattle would be the one way roller clutch housing that is usually held back by the "case saver" clip. It resides about mid-way down the transmission. To me it would just "clunk" rather than rattle though. (If said clip was broken or missing)

 

Thats where I'd start looking, I've built a few hundred 350's but never because they had a rattle...check the converter bolts.

 

Had a 71 C10 that had a strange rattle much like the one you are talking about, it ended up being a cracked flexplate.

 

Thanks fellas. I'll check it out this evening.

 

I had a similar issue and know it wasnt loose or cracked parts

likely something inside

 

Being it goes away in neutral i am going with, loose torque converter or cracked flexplate around mount holes

 

I had a rattle in my chevy truck. It only did it when I was loading it (taking off from a light, passing or pulling a hill). Ended up being the U joints. Not what I expected.

 

I had a shift shaft touching the exhaust that caused some wierd noises. Trans guys said it was the rear end. Rear end guys said it was the trans.

I should have just got under there and looked for myself...........

 

Well, I checked the flywheel and torque converter. Tight and no cracks. Now, its rattling the same in N as well. What would be spinning and causing a rattle while in gear AND N, but NOT in park or while in gear at a stop?

I have the opportunity to put in a 700r4. It's gonna take a little minor fab at the mount and a shorter driveshaft, but all very doable. I guess I'll need to figure out how to bypass the electronics, if it's even possible.


Aggrevation is setting in.