Its not the first time that ive found something done wrong on my truck that my cousin did for me, so im not to surprised that this is wrong as well. Im glad you guys pointed this out to me so i can fix it.

 

Only time I've seen shims on the front of an SAS was when the frame tube was in front of the body mount.

 

Looks like a CV up front might be the answer? Seems like Wabbit and others are recommending one.

 

Shims arent just for pinion angle when you use them in the front, they also add caster for better steering. the more lift, the more positive caster you need. Also if you dont have a cv joint in the driveshaft then you need the joint angles to match within a couple degrees otherwise you WILL GET VIBES. If you put a cv joint in, then the pumpkin needs to be angled directly at the transfercase, as 4crawler said. Buy a cheap protracter with a magnetic base(they are like 10 bucks) and measure the angle of the front and rear yokes, they should be within a couple degrees. If they are then your shaft is bent. Pretty simple

 

If you understand the deminsions of the 85 frame as to how Toyota mounted the Axle which is where the caster is set. Then if you know and understand caster prior to your build. Than no you do not need shims to set caster. If you understand operating angles your know that any driveshaft will produce vibrations at steep angles and increased speed.

 

Everyone says "a few degrees." What do you consider to be a few? 2 degrees difference between flange angles? 5?

I understand everything muddpigg is talking about, I just want to minimize what's going on.

 

Give it a go and post back.

 

Ahh.. ya, but shims are the easiest way to correct caster and driveline angles,not everyone has the ability to redesign things. As far as max operating angle of a u-joint I believe it depends alot on length and rpm, but anything over twelve degrees tends to lead to trouble

 

See below:
- http://www.4crawler.com/4x4/CheapTri...l#Measurements
- http://www.4crawler.com/4x4/ForSale/Shims.shtml#FAQ1

Typically 1-2 degrees off ideal to allow for pinion tip under load. Up front, might be closer to 0 if you want a smooth running shaft with the hubs locked.

 

x2...and that is not too steep of an angle. I run way more angle than that with no cv and it doesnt vibrate at all. Ship the shaft back to me and we will check the balance, We can at least eliminat the shaft as the problem. Or confirm.

 

^^that is some outstanding customer service

 

Here is some background on this rig. I built the rig in-house. The front axle was purchased from another guy, so we did not go through it at all. I mentioned to Rob at the time that the front 3rd had some slop in the pinion, and it felt like the pinion bearings were hosed. They were. In fact, the front was missing some teeth as well.

So, Rob pulled the 3rd and brought it down to me to rebuild it. Then he reinstalled everything. The dual cases were also bought from the same guy. All we did was switch the rear case from a fwd shift to a top shift case. . At first we had an issue with the case popping out of HI range under load. HD ball detent spring fixed that though.

To date, Rob has pulled the front shaft and driven around in both 2wd and 4wd. Hubs locked and unlocked with no vibes. So we isolated it to the shaft. I have not had the rig back at the shop though since he lives up in Breckenridge and its a hike to bring it into Greeley. So, its all been done over the phone with Rob. I am pretty sure its the shaft, but its very hard to tell. He sent me pics and the shaft is in phase correctly.

FWIW, I think a CV would help as well, but I have run standard joint shafts with no major vibes as well. Hell, I even build them myself on the bench with a dial indicator and don't balance them and they still do okay. If Rob could get the truck down to me, I could bolt in a different shaft to see if in fact that is the issue. But, the logistics and distance makes that a little hard.

I have ordered several shaft from Dave and they have all been good to go. So, I cannot say with all certainty that its the issue, but I appreciate Dave stepping up and helping Rob out. Thanks Dave!

 

WOW, that is GREAT customer service. And thanks to Scotty for chiming in as well..awesome vendor support. Addicted and Davez have been the best vendors I've worked with so far...

Anyway, the rear case was not purchased from the same guy as the front axle...thank god, or we would have issues. Instead, the case was a nearly new Marlin-built 4.7 23-spline case I bought from a guy who completed a project and decided he wanted something different. Scotty then took my stock t-case and made a crawler box, which seems to work fine.

I've had the driveshaft off several times, which eliminates noise in all areas, so I suppose it could be the balance of the shaft. I recalculated the angles this morning: there is about 4 degrees difference between the t-case and pinion flanges. Too much on a Toyota?

Thanks for the support. We're getting enough snow up here now that I'm at my wit's end trying to figure it out. Dave--thanks so much for the offer. Should I see balance weights somewhere on the shaft? Should I give you a call Monday to figure out shipping, etc?

 

With the problems of the 4.7 tcase kicking out doesn't sound like a Marlin setup as Marlin uses the cut of the gears to hold the tcase in gear same cut as Toyota uses. Marin has a patent on it so other 4.7 supplies have to use the HD detent. So if you no for sure it is Marlin some thing is off. Number 8 http://www.marlincrawler.com/tech/tr...d-technology#6 You might want to dig into this t-case.

4 degrees isn't to bad. I would think you'd be fine with shaft at lower road speeds. A fresh 3rd. Yep. I think you need to look at the tcase.

 

I actually had to swap the heavy duty detent ball and spring out for the stock one. The stock one keeps it in gear much better than the HD one. I haven't had a shifting problem now for a long time, especially after adding a heavy duty t-case mount.

 

Detent ball doesn't keep it in gear for the Toyota or Marlin gears.

Perhaps you should arrange to drop the rig off with Scotty C after all this is how he makes his money.

 

Naw, I think I'm just going to sell this b*$ch. I'm tired of dealing with it and it's probably the wrong hobby for a perfectionist like me. Sports cars don't have driveline angle problems and do really well in the snow, right?

 

you say you isolated it to the shaft, you are talking angles of the shaft (not bent/balanced)? i have the same prob, noises and all, found it to be angles. i really dont think ur shaft is bad. mine ~18º at the t case and ~10º at the pinion (front). w/o CV this is maxed angles and ~8º off parallel. ur pic looks similar to my set up.

i think high pinion will be a big improvement ($$$) ill be ordering one from inchworm

this sound right?

 

I don't think my operating angles are quite like yours but they are very close. What is your set-up (suspension, cases, etc.)? My gut feeling is that my angles are wrong... Thanks for responding.

 

88 runner, 4" TG SAS, single 4.7 case, tatton driveline(no CV). i jacked up the front axle, took the rear driveline off and ran 3rd gear..4hi hubs locked, unlocked and finaly no front driveline. was able to recreate the noise with the the shaft in place and it sounds like its coming from the tcase, kind of. its a new tcase and the exact same sound as with the old one. with out a doubt its the angles. ill tell you what, i go through ujoints like they are made out of plastic, no break though. i know alot of people say just run it, but like you i need the slightly higher speeds as well and this cant be good for the pinion bearing or the tcase innards.
do you know about what angle you have at the tcase?