Howdy Folks -
Figured I would post a quick follow up to this thread. I see it's grown a bit since my last reply, some additional questions have been asked and a PM popped into my inbox.
I am traveling for the next few months so M1009 is on the backburner. Then other financial priorities have put the M1009 back on schedule sometime in 2013.
Follow ups:
No tire/wheel changes during the lift. I don't believe changing wheel/tire size would affect driveline angles which are the source of my vibrations.
I changed both U joints on the rear driveshaft during my first troubleshooting session. No avail.
I purchased 2, 4, and 6° shims for my next troubleshooting session. I worked with my buddy, took some measurements, and threw the 6° shims in kicking the pinion down in attempt to make the pinion and t-case output parallel (that's the goal of playing the shim game). Got the pinion pointed 2° under the t-case output so that under power the axle can rotate up slightly and hopefully be in parallel with the t-case output. DO you own reading on this theory and come to your own conclusion. I feel under normal driving conditions at speeds that may induce driveshaft wiggles, pointing the pinion anywhere from 0-1.5° under tcase output is kosh. Again, not the topic of discussion, many threads about where to point pinions.
6° shims with my pinion 2° under was disaster. Huge vibrations. 4° and 2° shims lessened vibrations, but still worse than no shims. Tried pointing pinion up for shiggles, no improvements. Crappy day.
Lowered the t-case by flipping the position of the 1" spacers that on top of the frame lip. I played the shim game again and came up with something that is driveable but still wiggles. I can't recall what shims I have there. I'd take a peek but again I'm traveling and won't be back for while.
By lowering the t-case I now have an 09 with a pregnant belly. Not cool for breakover angle but at least I can drive it. I did measure angles at both Ujoints on the driveshaft and each Ujoint is bending around 22°. From my understanding this is a lot for Ujoints, period. I may get a couple thousand miles out of them if this was my final setup. However, I've been gather some parts...
Over the past few months I've gathered some parts and here is my plan. Yes I know, expressing dreams or setups that aren't finished doesn't really accomplish anything but this driveline issue basically prompted this entire surgery plan.
Picked up a 14 bolt for the rear, a D60 for the front, an NP205 as half of my 241/205 doubler. By using an NP205, you have a fixed yoke on the Tcase. This increases the X distance from the tcase output to the pinion which decrease the angles at both U joints on the driveshaft. However, by throwing in another Tcase inline, I will do the opposite, shortening the already short distance and increase Ujoint angles. There is really only one solution for the rear driveshaft in this setup and that is getting a double-cardon 3 Ujount drive shaft and rotating the rear axle so the pinion is parallel with the driveshaft (rear most driveshaft angle is 0°).
When the 09 is complete, the above configuration will hopefully eilliminate rear driveline angles. Costly, but should be able to conquer terrain and go down the street without worries.
Another alternative on the semi-cheap is to swap out the NP208 for something else like a 203 or a 205 that has a fixed yoke and get a double-cardon driveshaft. 4xshaft for a custom job, or pull something large from a junkyard and DIY.
The blazer has a short wheelbase and its driveline components are rather close together. When you start mucking with things, affects ripple larger, faster then in longer wheelbase vehicles.
Some Ideas:
- Lower t-case
- New rear Ujoints
- play the shim game
- fixed yoke t-case + double cardon driveshaft
Basically if you're on the cheap, play the shim game until you're satisfied.
Hope this makes sense. Haha, I'm actually recovering some a nasty stomach bug at a hospital in Singapore. I did proof this reply once and it flowed for the most part.
Hope this helps.
