Thump when stopping and starting.. Trans or something else?

[MikeT]

1997 2WD 4.0L Ranger 115K miles. I just had the transmission rebuilt and it shifts fine. The problem I am having is that when coming to a complete stop, just before you stop, I can feel a "thump". Then when I go to start, I get on the gas normally and I feel another 'thump". I called the transmission guy and he said, it could be the rear leaf springs and some bushings or the "pads" between the springs?? He also said that the motor mounts may gave gone bad but he looked at them and said they looked Ok. They are original to the truck and have never been replaced. All the shocks are new. His list of possible items is;

•Rear leaf spring bushings and or pads
•Motor mounts

Has anyone experienced this and figured it out? Are the leaf spring bushings easy to check/replace?? I figure since they had the transmission removed, they lubricated the yoke slide so I've ruled that out. It is driving me nuts!!!!

 

[gw33gp]

Do you have a spline joint in the driveshaft? They are known for this type of thump when the lube gets depleted. Taking it apart and re-lubing fixes the problem.

Oh, I see you said they lubricated the yoke slide. I would still take a look at that.

 

[MikeT]

You know, I say that they lubed that but I am just assuming that they did. If they didn't need to take that joint apart when they took out the driveshaft, then they probably didn't lube it. I'm going to look at that slip joint.

Next, do I need a "special" grease or can I use some BEL-RAY waterproof wheel bearing grease? I say that because that is what I have in the garage.

Thanks!

 

[gw33gp]

I think they use a special blue Teflon grease that you should be able to get at a Ford dealer. I don't know that it is needed. When I did it, I used a Krytox grease that had a Teflon/MoS2 blend. I did it over 100K miles ago and it is still working well. The BEL-RAY grease may work too but I don't know anything about it.

If you take it apart and lube it, make sure you maintain the orientation of the driveshaft.

 

[Dangerrangers]

Go for the safe side and lube the slip joint. It should all come apart easy seeing that the tranny was just out which of course means the drive shaft was out. Also check those u joints.