I've tried it all...HELP!

[99B3000]

I've spent weeks searching these forums and others like it to try to figure out my problem and I am at my wits end!

99 B3000, 3.0L, manual trans., 2wd, extended cab.

Problem: One or two clunk noises when accelerating from a complete stop (I know what you're thinking...keep reading). No noises during sharp turns or going over bumps in the road. No noises during braking. No trouble at all with clutch or shifting through gears. No clunking when going through gears, only when accelerating from dead stop. Can't reproduce sound by bouncing or rocking front end of vehicle. If I accelerate slowly enough it doesn't clunk.

Repaired in the last month:
1) U-joints (note: one piece drive shaft, no carrier bearing, no slip splines)
2) Both inner and outer tie rods
3) Wheel bearings
4) Drained, checked for broken gear teeth and filled differential
5) Drained and filled transmission fluid

Checked:
1) Ball joints - good
2) Checked for extra slop in the slip yoke where it comes out of the transmission - good
3) Transmission mount - good
4) Shocks - good
5) Control arm bushings - good
6) Sway bar and links - good
7) Brake calipers and caliper brackets - good

Any other ideas???

 

[SenorNoob]

I've just subscribed to this thread. I have what sounds like the same problem. Best I can figure it's excessive gear wear in the rear differential.

 

[adsm08]

Repaired in the last month:
1) U-joints (note: one piece drive shaft, no carrier bearing, no slip splines)


Any other ideas???

Have you tried greasing the slip splines? All drive shafts have to have them or the transmission breaks when the rear suspension flexes. Your's are just on the yoke in the transmission, not in a boot in the middle of the drive shaft.

 

[martin]

Have you checked for the less obvious things like, loose battery mount, spare tyre, jack and associated componants, left side motor mount?

 

[99B3000]

Adsm08 - So the slip splines must be on the inside of the yoke?

Martin - I did check the less obvious things. Yesterday I thought of the motor mounts, but the truck was in the shop all day getting new valve cover gaskets. Hopefully I will get home before dark today and I can check them.


Thanks so much for the replies!

 

[99B3000]

Whats the best way to check motor mounts on a manual transmission?

 

[Earl43P]

Set the parking brake hard.

Put it in 1st and then reverse and let the clutch out enough that the engine strains to move the truck against the brake. Have someone watch the motor mounts and see if a gap appears while it's under that torque load.

 

[99B3000]

If I grease the slip spines on the yoke in the transmission, do I have to worry about the grease mixing with the transmission fluid?

 

[SenorNoob]

Have you checked for the less obvious things like, loose battery mount, spare tyre, jack and associated componants, left side motor mount?

I don't know why I didn't even think about it before, but this applies to me. Nothing in my bed is bolted down.....