700R4 rattle

[Steelrat]

Yesterday I noticed a rattling sound when the car is at 2000 rpm in 2nd gear. It is breif and goes away when the rmp drops or goes higher than 2000 rpm. The sound seems to be coming from the top of the tranny near the front or under the shifter. I will get under it this weekend and see if there is something loose, but am concerned it could be an internal issues.

Any one expereince this?

[Steelrat]

My mistake. It is 3rd gear at 2000 rpm

[6'9"Witha69]

Could be a harmonic from the driveshaft or related component which causes a loose trans mount or other bolt to rattle. Maybe the U joint at the slip yoke?

These are the types of 700 rattles I am used to. Also, if you are sure it is the rear, ok, but I have had loose TC shields make noises at certain speeds as well. Perhaps do a nu8t and bolt of the whole Trans area and check for slack in the U joint.

At least that's where I would start.

[6'9"Witha69]

I wrote all that having misread that it wasn't the front. It is. Ooops. I would still nut and bolt it first.

[Steelrat]

thanks will check all the nuts, bolts, etc

[Steelrat]

Well I tightened every nut and bolt I could get a hold of from exhaust clamps, cable brackets, shifter, brackets/linkages, etc to cross member bolts. I dont have a TC shield. The sound is still there. I dropped in to a local Trans shop and took the owner for a ride and he listened to it, he said he thinks it may be a flex plate sound, but as it appears to come from the front and top of the tranny he cant be sure.

Would the next step be to re-torque the flex plate bolts, or am I facing other issues? 60 ft-lbs is correct I believe. Should I be using Thread Locker on the bolts?

[6'9"Witha69]

Should I be using Thread Locker on the bolts?

I always do. Better safe than sorry.

[Steelrat]

thanks