Is this a good oil choice?

This last weekend I took out the Getrag, tore it apart, and had all new bearings pressed onto input shaft, output shaft, and counter shaft. It got rid of the grinding noise at low RPM's in gear, but it seems louder now overall. I was wondering if this is due to my using synthetic instead of dino juice like I had in it before.

Should I use an oil stabilizer like lucas or STP in it?

Avery

1991 D250 5spd, pump turned up

 

good choice, most everyone here will agree with using synthetic. some add something like syncromesh or a similar product if they are using the truck lightly.

Did you over fill by a 1.5 quarts or more? That is a good idea too, and can quiet some noise I guess.

You may want to run that oil for a bit as a break in oil then change it to clean out any leftover shavings or other crap.

welcome and keep asking questions these guys are great.

 

Yeah, I overfilled by about a quart. I figure I can make the other half quart up with some sticky stuff like STP.

Good idea on the break-in. How many miles do you think?

 

5W-30 full-synthetic seems to be the oil of choice for the Getrag.

Factory-fill is 3.5-quarts; I use five quarts.

Search around here to see about a kerjillion ideas on various methods of over-filling and dip-sticking.