Discussion in 'Builds and Fabricators Forum' started by Leftlane, Jun 2, 2013.
check for loose u bolts or bad center pins in the rear for a possible cause
Thanks. I took your advice, got out the torque wrench, and crawled under to find some of the 75ft/lb U-bolt nuts had backed off a bit. Not sure the problem is entirely gone, but it's likely better by some degree.
Meanwhile, I've been having fun doing little things. I mention the RAM mounts. Now that the last of the 1" ball mounts came in, I got everything mounted the way I wanted:
Last year a friend and I flew one way from CA to CO, fixed up a '69 CJ-5 Jeep that had been sitting dormant in a barn for >10yrs, and then drove it 1500ish miles back home using back-roads and smaller highways. He brought RAM mounts (with suction cups) on that adventure and it made me a believer. The cupholders are "No Party Foul" style since they rotate on two axes. What became apparent to me on that trip was a single 12v cigarette lighter output wasn't going to cut the mustard. So I installed this while I was at it - two 12v outlets and two USB outlets:
Since I was working on gussied-up items instead of working on things that I'll really need when I eventually run the Rubicon (my real goal with this thing), I finally covered up the shifter ball turret with a Lokar universal shifter boot:
I cleaned up my HiLift jack and mounted it to the DirtWorx bumper:
And, best of all, I cajoled my entire family out to get ice cream on a sunny California day for their very first ride in the Blue Lemon. This is what the last 1.5 yrs work has been for:
Really like the looks and build direction of this one.
Has that original/patina look, but a reliable 350 and fresh suspension, wheel and tires.
I agree completely, I like this Jeep very much. It just has the right look and stuff.
Cool. Nothing like cruising it with the whole fam in there!
I wrote the above about a year and four months ago. I was thinking about that post last weekend...
I wanted to take the Blue Lemon to Cars and Coffee early Sunday morning. Saturday I went over the nuts and bolts so I'd feel comfortable driving it a few cities away to the show. I'd had a nagging feeling as the Jeep seemed to be clanking and thunking more than normal. Sure enough, by the time I'd gotten on the creeper and was checking out the driveshaft, I noticed the rearmost U-joint had busted at the trunnion and taken a cap's wall out with it. It was holding together, but it wasn't long for this world. Good thing I checked. It's one of those reinforcing moments where you feel justified carving out a few hours based on little more than a nagging voice in your head.
I managed to run out to the local parts slinger and replace my busted Moog USA made joint with some cheap Chinese thing and get everything buttoned up to make the show on Sunday morning (excellent turn out - everything from each era of automobile showed up from the latest MacClaren, a slew of Ferrari, American muscle of all type, and the really old stuff like Model T's and even a Simplex - which I'd never seen before. Heck, even my clapped out, patina'd, hacked CJ5 drew a few admirers).
Being concerned that I've got a setup that's going to chew up U-joints, I took the latest measurements today:
The reason for the new differences are:
- fabricated 1" drop mount spacers for the trans/tcase
- engine swap to 350 Chevrolet with new motor mount locations
- 6° steel shims in the rear axle spring perches
The good news is that both operating angles are now <15°, which was my original goal. The bad news is that before I had the tcase output and the differential pinion in parallel and now they aren't. This artice suggests that to run a conventional 2 U-joint driveshaft, operating angles should be less than 15° (check) and the tcase output and pinion need to be within 1° of each other (fail). It goes on to say:
So maybe I'm headed for a double cardan (CV) shaft after all. I'd hate to drop the tcase any further for ground clearance reasons. Guess I'm going to call Tom Woods and get their take on my situation.
One more thing... there's a slight possibility I forgot to grease that original (new) Moog U-joint when I put it in earlier this year. I just don't remember doing it. That could certainly cause my busted U-joint. Trying to grapple with that and all these odd angles. It's probably a combination of the two.
That u-joint math is confusing to say the least, youd think point rear diff at t-case would be right but... Really like your Jeep by the way!
I too have some nagging rear drive line issues. When I tried dropping the t-case the vibs got worse so I haven't figured it out yet.
Great thread, great build, great jeep. Thanks for posting!
Thanks for the comments, all. Much appreciated.
So I call Tom Wood's Custom Drive Shafts and who do I get on the phone but Tom Woods himself! Didn't expect that. We chat about my current situation and his recommendation is... wait for it... a C.V. drive shaft. Okay, we all saw that coming but I like some consistency in my world (the website info was exactly what framed our conversation).
Given my current geometry even with my WP 6° shims, the diff's pinion is still not high enough. It is not pointed at the t-case output such as a double cardan shaft requires. Tom tells me he can send me some 10° steel shims for a reasonable sum. When I note that I've got the early CJ 1.75" width springs, he offers to shave down his shims for me to my specs. Believe me, after working over the Warrior Products 2" shims with an angle grinder to fit my springs this is welcome news!
Then he tells me I could remove my 1" t-case drop mounts were I to go with a C.V. shaft. The promise of restoring my lost ground clearance was enough to push me over the edge. I ordered up the C.V. shaft and a set of axle shims (3rd time's a charm on those).
Today, after I got home from work, the UPS man had this bit of coolness waiting for me:
It's worth noting I had to remove my current 2 u-joint shaft and then pop off the yoke (with its 1 1/8" nut) at the t-case to count the splines before I could place my order. The C.V. driveshaft requires a specific yoke due to the way the bolts orient around the U-joint caps on the forward-most joint. I have the 10 spline output shaft on my Dana 20 (as opposed to the 26 spline).
Also, I've read in some threads that extreme pinion rotation can cause a condition where the gear lube in the pumpkin isn't getting to the pinion bearing, causing premature failure. How might I handle that with these 10° shims? I was thinking I could back the CJ onto some ramps to tilt the rear down a bit and fill it that way. I'd have to measure if that was enough. Looking at my original measurements before I started playing with all this, it seems I'd only need to get the pinion at 5° for the filling.
My goal is to try to get to the install this weekend. There's one issue - space. The CV is about 4" wide and I've got 3 1/4" between the mufflers I had installed to quiet down the BL. I fully expect this shaft to not fit between the mufflers. Maybe 3rd time will be a charm on the mufflers too. I kept the Dynomax bullets, which would allow enough space, but DANG are those things loud! They do sound good, but I want to take road trips in this Jeep without bleeding ears. Anyway, stay tuned to see how this all turns out.
It's what i run a cv, i have 5-6" of suspension lift, almost the same lenght of DS. My pumpkin is way up, never had problem and on my test ride, never seen any excessive heat on the pignon bearing.
Great work on the Jeep.
CJ driveshaft in place
I got the new 10° shims installed, raised the trans/t-case back to the original height (removed my 1" spacers), and installed the driveshaft. Okay, less words, more photos.
Better rear u-joint angle:
Better overall ground clearance than before:
Pretty good, but all is not entirely well in the land of blue lemons:
That dent in the passenger side muffler is from the stock driveshaft, not this one, but it will undoubtedly hit there again. Also notice the less-than-a-finger's width between the front of the shaft and the driver's side muffler. Lastly, you'll spot the goofy jog to the driver's side the shaft takes. That's been there since I put in the motor. Probably should sort that out.
I will say that the CJ runs way smoother. It's absolutely perceptible. There was always a vibration when starting off from a dead stop when first blending the clutch and gas to get myself moving. Now that is simply gone.
Next immediate things:
figure out what to do about proximity of driveshaft to mufflers
measure current angles to compare to pre-CV/pre-10° shim measurements
I need to button this up to take it for its first off-road trip in the next month or so. Gonna try for Bald Mountain trail near Shaver Lake as a shakedown run. So far its been only to work, car shows, and ice cream shops. Need to get it off road before I really hit a new low and do something nutty like drive it to the mall.
Wow I'm jealous of that cross member position! Can't wait until I can take the inch of spacers out of ours....someday.
Any updates on this CJ?
I'd love to see more of this Jeep as well... I really like it!
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