Acceptable pinion angle with lift

[Cadaver]

Trying to sort out vibration issue since installing an RTE 3" and GBR DC front DS on my 98D1. What is an acceptable angle difference in the rear? I measured about 5 or 6 times and the max differences was 2.5 deg and the min was 2.0 deg difference between the bottom of the e-brake drum and the flat surface of the rear diff. Is this difference significant, or should I strive to change the rear pinion anlge by shimming the rear links so that there is exactly 0 deg diff, or are my measurements acceptable for my setup?

The details if you care:
Im getting a vib at 60-70mph and cant seem to chase it down. The vibration seems to get significantly better with the rear shaft out. It seems more of a harmonic style vibration as it feels SOME better above 70mph. What Ive done thusfar in the last week
1. balance tires
2. The front GBR DC ds was professionally rebuilt and rebalanced.
3. The rear shaft is the stock u-joint rear. I removed and the ujoints are silky smooth with no play whatsoever.

To spice it up some, I am getting a funky growl from what seems to be near the t-case when I slow down to a stop from approx 15-5mph. So, Im starting to get concerned about the tcase output flange and bearing. Plus there is some case seepage in the front, more than the usual. But, Im not ready to blame this noise entirely on the output bearing and still considering a poor pinion agreement in the rear driveshaft.

Anyone care to advise?

Thanks friends.

 

[ChicagoDon]

Have you tried it without the front shaft? 2.5* should be perfect for the rear.

 

[Cadaver]

Hey Don, thanks for the response. I did, as a matter fact. Strangely, without the front shaft I noticed some improvement as well. This is what prompted me to have the front driveshaft inspected. Turned out the center ball in the cardon joint was shot. The machinist replaced it, replaced all 3 u-joints, and balanced the entire assembly. I reinstalled the "new" front DS, and tested it. Still had that annoying vibration beginning at 60-65.

The pinion measurements above were with the rear DS out. I am about to drive it with the front DS only to reassess the situation. Generally, I tackle my Rover troubles rather methodically. However, Ive become confused with the fact that Im getting improvement with either DS removed. Leading me to believe Im having trouble with the front and the rear. I realize removing a driveshaft and locking the CDL for a test, I am essentially only narrowing my problems down to front or rear. Im wondering if, for some reason, my stock rear DS is not up to the 2.5 angle difference and I will essentially need a rear DC shaft. I suppose I could attempt to shim the rear links and see if I can gain some improvement.

The vibration isnt terrible, its there, noticeable, and definitely not normal. But its bad enough that it feels like damage may occur if its not corrected.

Any ides Don? Anyone else?

 

[barefoot]

how did the rear joints feel when you had the shaft out? if they are very easy to turn or just flop from one position to another they are prob bad even though you dont feel any side to side or "twisty" movement. they shouldnt be tight but they shouldnt just easily flop around either.

from my limited experience...driving with only one known good shaft can be misleading as far as vibes go. my guess is that having only one shaft in puts more stress on other 10 yr old components and makes it hard to tell whats going on!

for instance. after i just did the front joints i had to run to napa with just the front shaft in only to get another joint for the rear. i had vibes that werent even there before either shaft were removed. finished the rear...put it all back together and no vibes!

so....do the joints and go from there....they are cheap and you said you were going to remove the rear ds again anyway!

 

[Cadaver]

Thanks Barefoot. The rear ujoints moved or "flopped" relatively easily. They did so smoothly and Im a nutcase with the grease, so they were maintained well. I agree with your logic and honestly, Im confident that the rear ujoints are the originals. Couldnt hurt to replace them if only for piece of mind. I'll do that tomorrow if I get out of work early enough and report results. Any specific brand or type you people recommend?

Since the rear DS is out, I test drove it with the front only. Vibrations seem much less intense and are now postponed until approx 75 mph.

 

[barefoot]

well, i used precision #344 from napa which work and are greasable for $20/jointx2 per shaft....get an extra! however, do some searching....there is some debate as to whether they are worth a shit or not! most seem to prefer the spicers but i think the complaints with them is availability/price.

 

[Cadaver]

I'll check napa tomorrow.

The driveshaft specialist that rebuilt my GBR DC front DS installed 3 spicers. No wonder that thing cost me $185. I nearly shit. He is an hour away and supposedly the best (ie only) one in Western KY. But, found out he didnt balance the front shaft with the spacer I gave him. He said it wont make a difference. Makes me wonder, especially when the spacer was marked for position when I got it originally.

 

[bazzle]

Auto D1s are susceptible to rumble from the front if lifted.
Rover even puts the joints out of phase by one spline to try to reduce on Standard car. Are yours in phase or out?

Bazzle

 

[ChicagoDon]

I'll check napa tomorrow.

The driveshaft specialist that rebuilt my GBR DC front DS installed 3 spicers. No wonder that thing cost me $185. I nearly shit. He is an hour away and supposedly the best (ie only) one in Western KY. But, found out he didnt balance the front shaft with the spacer I gave him. He said it wont make a difference. Makes me wonder, especially when the spacer was marked for position when I got it originally.

The spacer shouldnt matter. I have front and rear DC shafts, 4" of lift, and toyota axles with slightly improper pinion offsets. I had both of my driveshafts re-done after the axle swap, neither was balanced with the spacer, and I dont have vibes.

I'd honestly be more suspect of the front end than the rear. What is your front pinion angle in relation to your driveshaft operating angle? Is the driveshaft directly in-line with the pinion or off by a few degrees?

If you do decide to go with a rear DC shaft, ive got a 1310 spicer CV, rover 1310 flange, and 3 u-joints. All of these parts have less than 100mi on them, aka new. left over from when I was experimenting with different stuff right after i first finished the axle swap. I can have those parts made into a HD rear DC shaft for $250 if you decide to go that route. Sorry for the shameless plug.

 

[rovercanus]

For the love of God man! Don't get the shitty NAPA u-joints! They are over priced Japanese shit that will only last a couple of k if your lucky and fail in the worst possible place. Mine failed in some ghetto suburb of Philly! If you look at the things they have tiny end caps, tiny rollers and tiny little attitudes like Japanese transistors.
Go to Auto Zone (Yes, I said Auto Zone!) and get the PDQ 1-0005 u-joints. They are by God, made in the US of A Neapco u-joints with grease zerks on the end caps. These will fit all the Rover models, D1, D2, and RRC.
I just changed out a shitty 344 poser u-joint that disintergrated as I was pressing it out. Wish I took pictures.

 

[skippy3k]

This will be an interesting thread to follow. I lifted my P38 about 3" and have been chasing down a 30 mph vibration. I removed the front DS and the vibrations got better, so I got a GBR double cardon driveshaft. That made everything worse. I put the stock back on and then removed the rear DS. That kind of made things better, but not really. The end result is no matter which DS I remove, it doesn't narrow anything down....similar to your problem. AND I've also got a slight growl when I let off the gas.

I'll back away now and see what the others chime in with.

 

[Mike_Rupp]

Have you tried shimming the trailing links to change the angle a little? On mine, I had to go through several different shims to get the right setting. If I remember correctly, my rear pinion is about a degree high.

I'd recommend just varying the pinion angle and see what happens. When I did mine, it was more trial and error instead of trying to get the angle perfect.

 

[MUSKYMAN]

This will be an interesting thread to follow. I lifted my P38 about 3" and have been chasing down a 30 mph vibration. I removed the front DS and the vibrations got better, so I got a GBR double cardon driveshaft. That made everything worse. I put the stock back on and then removed the rear DS. That kind of made things better, but not really. The end result is no matter which DS I remove, it doesn't narrow anything down....similar to your problem. AND I've also got a slight growl when I let off the gas.

I'll back away now and see what the others chime in with.

this is easy...you are getting vibes at both ends!!!

the remove the driveshaft trick only tracks down a new vibe in a otherwise vibe free truck that has not had any changes since it was vibe free.

you need to take each end one at a time and get the pinion angles correct for the style of shafts you are running. single cardon shaft the drive and driven flanges need to be paralell. double cardon shafts need the pinion to be within 3* of alignment with the main shaft in all planes and then it divides the total angle at the drive flange of the transfercase.

 

[Cadaver]

How should I measure the front? Diff angle and main shaft angle only? Should I measure the front output flange?

Mike, I grabbed a handfull of M20 washers from Lowe's. I may try to shim the rear link down a tad and see if that helps. And I will change out the rear U joints (picked up some PDQ1-0005 ujoints at AZ today). I'll return.

 

[MUSKYMAN]

get a magnetic angle finder

the flat part on the 3rd member is the same as the pinion angle...the driven flange/pinion flange is 90* to the same angle.

just use the angle finder on the shaft itself to get that angle.

 

[Cadaver]

The angle difference between the front diff and front DC DS is 1.5 deg. Im hoping to get home from work early tomorrow and add a washer to each side of the rear links. As well as replace the ujoints.

Thanks for all the help. It is appreciated.

 

[Cadaver]

Update. I was able to get the angle difference between the rear diff and the bottom of the e-brake drum to slightly under one degree. Also, replaced rear ujoints. Vibration feels some better, but not much.

I've noticed something that might play a role, if not THE role in the vibration. When turning sharp right at slow speeds, I hear a low faint whine from the rear that comes and goes with what appears to be tire speed. Actually, the clicking of the detroit is louder. The 3rd member is less than 6 months old out of GBR with a detroit locker and fresh 4.11s.

The vibrations seem to be more in the rear of the truck and I cant feel them in the CDL shifter handle.

I think I might check the tightness of the wheel bearings (fairly new). Im wondering if I might have a bent steel wheel. Or, is it possible the rear axles could be bent???? They are rovertracks HD rear axles and Ive had them for a while. I keep telling myself that this is related to the lift as the vibrations began once the RTE 3" was installed.

Suggestions anyone?

 

[MontrealRR90]

Update. I was able to get the angle difference between the rear diff and the bottom of the e-brake drum to slightly under one degree. Also, replaced rear ujoints. Vibration feels some better, but not much.

I've noticed something that might play a role, if not THE role in the vibration. When turning sharp right at slow speeds, I hear a low faint whine from the rear that comes and goes with what appears to be tire speed. Actually, the clicking of the detroit is louder. The 3rd member is less than 6 months old out of GBR with a detroit locker and fresh 4.11s.

The vibrations seem to be more in the rear of the truck and I cant feel them in the CDL shifter handle.

I think I might check the tightness of the wheel bearings (fairly new). Im wondering if I might have a bent steel wheel. Or, is it possible the rear axles could be bent???? They are rovertracks HD rear axles and Ive had them for a while. I keep telling myself that this is related to the lift as the vibrations began once the RTE 3" was installed.

Suggestions anyone?

I would check all the weels in the air and look for play in all bearings.Could just be a bearing or it might need a shim to take out the play.I had a wheel that could not figure why there was play in it.After balancing the tire inspecting the bearing and rim.A buddy of mine Took out the ABS sensor and added a shim inside were the sensor goes in and the play went away. I did not know there was shims in there.

 

[Cadaver]

Found some play in the rear bearings, solved the whinning noise, but vibration is still there. Im starting from scratch again and will remove the rear DS and retest.

 

[Cadaver]

OK, Ive made tremendous progress... sort of.

Im back to square one. Removed the front GBR DC DS and tested the ride. Smmmoooooth up to 80. Im happy with that. Reinstalled front shaft and vibrations are there. Im not happy that I just spent $280 having the 6mo old GBR shaft rebuilt locally with new Spicer joints, DC joint, and rebalance without the output flange spacer.

Its either the front shaft or the angle of the shaft with the diff. Right?