Small "bump" when accelerating in 1st and/or 2nd gear

[HighPlainsShifter]

I have a 98 Ranger, 3.0L, 4WD, manual trans.

When I am accelerating in 1st or 2nd gears the truck often gives a slight bump. After 2nd gear it doesn’t seem to do this and I am in 2WD at the time (not 4WD). It is a lot more noticeable in warm weather. My thoughts are that it is the rear differential slipping and I may try using a friction modification additive. Any ideas on other causes or fixes?

 

[TWT51]

transmission

is this automatic trans ? probably low on transmission fluid or needs to time for filter and fluid change on transmission

 

[Jon]

I've had similar issues and it was the transmission fluid, as TWT51 said above.

 

[lovemyranger]

I have a 98 Ranger, 3.0L, 4WD, manual trans.

When I am accelerating in 1st or 2nd gears the truck often gives a slight bump. After 2nd gear it doesn’t seem to do this and I am in 2WD at the time (not 4WD). It is a lot more noticeable in warm weather. My thoughts are that it is the rear differential slipping and I may try using a friction modification additive. Any ideas on other causes or fixes?

check and make sure one of the engine or tranny mounts ar not broken.