Noise when shifting from Reverse to Drive...

[jp887]

My 97 Ranger 4x4 (4.0 L) is making a metallic "ting" noise when shifting between reverse and drive (automatic transmission). Its one of those annoying things that doesn't happen all the time but seems to be getting more frequent. It often happens as I pull away, not always immediately when the gear first engages. Best I can tell is that it is coming from around the middle of the truck somewhere and it seems to happen more frequently if I stop on a hill.

I know my centre support bearing for the driveshaft needs replacing and is causing the shaft to shake a little at certain speeds. Could this metallic noise be related to the support bearing? I thought this was unlikely because although the rubber around the bearing is worn it doesn't look so worn that metal is touching metal yet, but it does allow for some lateral movement in the driveshaft.

I also noticed that the rear differential case moves a bit when shifting from Reverse to Drive (rotates around the rear axel a small amount). Is it normal for the diff case to move a little like this or could this be part of the problem? I don't think the noise is coming from the diff but was surprised to see it moving when I looked under the truck while someone shifted the transmission.

Any thoughts/advice much appreciated... hopefully I don't need a new transmission

 

[adsm08]

You need to go get some teflon grease and grease up the center slip joint of the drive shaft.

 

[jp887]

Nice, thanks for that. I just read up about this and it certainly seems to be a common cause for drive shaft noise. I'll give that a go and see if it fixes the noise.
Sorry for the rookie question but is the movement in the rear diff normal?

 

[Tedybear]

A bit of play in the rear diff is normal.

Have a check of your U-Joints while under it doing the grease bit. Block the front tires and put the back end on a set of jack stands. Transmission to neutral and move the drive shaft back/forth. That should help isolate the sound.

S-

 

[adsm08]

Yes. The diff has to have some play in it to work. If you set it to zero backlash (the amount of play between the ring and pinion gears) the diff locks up because of the shape of the gear teeth.

 

[jp887]

Thanks for the advice. Much appreciated!