Shudder at speed?

[orion_134]

I installed some 33" BFG All-terrains (used) that were already mounted and balanced and took it for a test drive and it seemed to have a shudder...not at a constant pace. One would think that this is caused from tire imbalance, except for the fact that this is almost the same shudder that I get with the cruise control on going about 70-75 on the interstate with my old tires. Is my tranny not liking the additional rolling resistance and weight of these tires? I seem to notice it more at the lower rpm's, maybe 1500ish. The motor sounds exactly the same and the shudder is still noticeable when I let off the gas, just not as prominent.
Thanks,
Jesse

 

[Tail_Gunner]

Do you have a lift kit? Sounds to me like it may be a driveshaft/carrier bearing angle vibration.

 

[JLDickmon]

or a torque convertor clutch shudder...

 

[orion_134]

The latter is what I am thinking. Tranny fluid is still red, but smells iffy (not burnt, just iffy). Also, when I put it in gear and let off the brake with no throttle pressure, it doesn't seem to want to move like it did before. I think I am just noticing too much stuff because I'm paranoid about the tires. I'm just going to get them balanced and go from there.
What do y'all think?
Jesse

 

[big_rooster]

Little known secret when you balance bfg's always put the valvestem inbetween the O's in good. There is extra material 180* degrees off to counter balence the weight of the valve stem. Put the tire on that way and it takes less weight to balence.

 

[JLDickmon]

if you're going to explore that, the builder's mark should be a white or red dot on the exterior sidewall roughly the size of a dime...

 

[orion_134]

Little known secret when you balance bfg's always put the valvestem inbetween the O's in good. There is extra material 180* degrees off to counter balence the weight of the valve stem. Put the tire on that way and it takes less weight to balence.

Did not know that but I will pass it on...thanks!
Jesse

 

[orion_134]

Definitely thinking it's tc...can feel it once tc locks up and it was much worse today...need to get on with the repairs soon, now if I can just get straight answers on what I need to do...Replace the tc, put on a bypass filter as well as replace the screen, install gauge, flush the fluid (or should I do that before I put in the new tc?), do the front pump mod I hear about and be done with it? Am I missing anything? I've got a 15 hour trip one way coming up and on the way back I'm wagging a trailer so I need to get this done soon.
Thanks guys,
Jesse

 

[JLDickmon]

first thing you do if you're thinking that way, is flush the fluid and add an anti-shudder additive, like Justice Brothers, Ever-Wear, etc...

 

[orion_134]

I flushed the fluid 17k ago, but that is just handicapping the problem and the truck has 207k on it, I am pretty sure that the tc is going to go and I don't want it to wipe put the rest of the tranny in the process.
Jesse