This is on my stock tranny (4L60E) in an 02 envoy, I was taking my tandem axle 14' trailer (about 1300 lbs) for it's annual inspection and I felt a shudder under load. I'm almost positive the TC was locked in OD...about 50-55 MPH....usually is.I was accelerating and when I was between 1/3-1/2 throttle, TC remained locked and the vehicle started to shudder but was progressive and not a hard shudder but almost felt like a bad U-joint. When I apply the gas at 50 ish, there is no shudder but when I hold the throttle position the shudder comes in lightly then amplifies and goes away when I let off.There is no spike in RPM like a clutch pack slipping but I don't know...shifts fine and runs fine the rest of the time.I have replaced the separator plate, 1-2 and 2-3 acc pistons and have the vette servo. Trans has 182K miles and fluid looks great, replaced 10K miles ago.Fluid has always been replaced at 30-40K intervalsRear was changed from factory 8.0" to a 9.5" SF and I just switched to Redline Heavy Shockproof fluid.U-Joints are new and driveshaft was shortened and balanced.Just curious if this could be a trans issue or not and if so where to look.

this could be it, but maybe the TT tongue weight is causing the axle to bend backwards and the angle of the drive shaft is a little higher thus causing the stutter you describe.

Possibly the torque converter lock up is slipping.BTC

My guess is the driveshaft. It is the only non stock item and logically the first place to look. Having sold and installed a lot of rebuilt driveshafts over the years I have had shakes from initial installation to various times and mileages after installation. Issues have ranged from the yokes being slightly out of phase to my supplier trying a slightly cheaper u-joint in an attempt to improve his bottom line. It could also being something new like the rear main loosening up and the crank is flexing. There are lots of possibilities. At the mileage you have mentioned I would buy a new vrhicle instead of throwing money at a possibly hard to locate shake. Randy

the shorter the drive shaft becomes , the possibility of a driveline shudder increases . The degree of angle of the output shaft needs to be VERY close to the same angle of the pinion shaft on the rear end. This can be done using an inexpensive angle gauge from the home depot or other places . If the truck has leaf springs in the rear the angle of the pinion can fairly easily be changed with the use of simple wedges available through e-bay , amazon or parts houses,placed between the axle mounting plate and the leaf spring.I had the same problem with a Jeep Cherokee that came from the factory doing this and was finally fixed by myself when I learned of this procedure Good luck,

dannydimitt wrote:the shorter the drive shaft becomes , the possibility of a driveline shudder increases . The degree of angle of the output shaft needs to be VERY close to the same angle of the pinion shaft on the rear end. This can be done using an inexpensive angle gauge from the home depot or other places . If the truck has leaf springs in the rear the angle of the pinion can fairly easily be changed with the use of simple wedges available through e-bay , amazon or parts houses,placed between the axle mounting plate and the leaf spring.I had the same problem with a Jeep Cherokee that came from the factory doing this and was finally fixed by myself when I learned of this procedure Good luck,Here is the part # for the angle finder I used Swanson tools part # AF006M

What would cause a shudder under load | Good Sam Community

16 Replies

dannydimitt
Explorer
Apr 01, 2013
dannydimitt wrote:
dannydimitt wrote:
the shorter the drive shaft becomes , the possibility of a driveline shudder
increases . The degree of angle of the output shaft needs to be VERY close to the same angle of the pinion shaft on the rear end. This can be done using an inexpensive angle gauge from the home depot or other places . If the truck has leaf springs in the rear the angle of the pinion can fairly easily be changed with the use of simple wedges available through e-bay , amazon or parts houses,placed between the axle mounting plate and the leaf spring.
I had the same problem with a Jeep Cherokee that came from the factory doing this and was finally fixed by myself when I learned of this procedure

Good luck,

Here is the part # for the angle finder I used
Swanson tools part # AF006M

A plethora of information can be gleaned from this web site
www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml
dannydimitt
Explorer
Apr 01, 2013
dannydimitt wrote:
the shorter the drive shaft becomes , the possibility of a driveline shudder
increases . The degree of angle of the output shaft needs to be VERY close to the same angle of the pinion shaft on the rear end. This can be done using an inexpensive angle gauge from the home depot or other places . If the truck has leaf springs in the rear the angle of the pinion can fairly easily be changed with the use of simple wedges available through e-bay , amazon or parts houses,placed between the axle mounting plate and the leaf spring.
I had the same problem with a Jeep Cherokee that came from the factory doing this and was finally fixed by myself when I learned of this procedure

Good luck,

Here is the part # for the angle finder I used
Swanson tools part # AF006M
dannydimitt
Explorer
Apr 01, 2013
the shorter the drive shaft becomes , the possibility of a driveline shudder
increases . The degree of angle of the output shaft needs to be VERY close to the same angle of the pinion shaft on the rear end. This can be done using an inexpensive angle gauge from the home depot or other places . If the truck has leaf springs in the rear the angle of the pinion can fairly easily be changed with the use of simple wedges available through e-bay , amazon or parts houses,placed between the axle mounting plate and the leaf spring.
I had the same problem with a Jeep Cherokee that came from the factory doing this and was finally fixed by myself when I learned of this procedure
Good luck,
randallb
Explorer
Apr 01, 2013
My guess is the driveshaft. It is the only non stock item and logically the first place to look. Having sold and installed a lot of rebuilt driveshafts over the years I have had shakes from initial installation to various times and mileages after installation. Issues have ranged from the yokes being slightly out of phase to my supplier trying a slightly cheaper u-joint in an attempt to improve his bottom line. It could also being something new like the rear main loosening up and the crank is flexing. There are lots of possibilities. At the mileage you have mentioned I would buy a new vrhicle instead of throwing money at a possibly hard to locate shake.
Randy
weasel4
Explorer
Mar 31, 2013
Possibly the torque converter lock up is slipping.
BTC
old_guy
Explorer
Mar 31, 2013
this could be it, but maybe the TT tongue weight is causing the axle to bend backwards and the angle of the drive shaft is a little higher thus causing the stutter you describe.

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What would cause a shudder under load

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