Front Drive Shaft Binding

[cgbexec]

Twin Sticks came from Wild Horses.

The angle at the pinion is not as severe as the angle at the transfer case. The motor mounts are not stock and the engine is sitting about 1" higher than it did originally although the old mounts were original and were worn pretty good. If I could get the engine to drop about 1", it would free up some of the bind, but not all. As far as the springs, they are currently about 18" in their current compressed state. Due to the fact that the coils sit on the new radius arms, I am not sure if they are longer than a normal 3.5" lift. I bought the suspension as a complete system. Perhaps the coils are too long and I really have a 5.5" lift and that is causing my grief. As far as the radius arms, they are installed and everything looks good. Rotating the axel pinion up 1 - 2 inches may free up the bind at level road driving, but off road this is not going to work.

I am going to purchase a high angle front drive shaft anyway, but I think I need to contact JBG and make sure they sent the correct front springs. The more I think about it the more I think I may have the 5.5" coils instead of the 3.5" coils.

Thanks,

Chris B.

 

[chuck]

Measure from the bottom of the frame to the top of the axle tube. Stock is 7", a 3.5" lift will give you 10.5", without the body yours may measure 11 or a little more. With a 5.5" lift and no body you should get around 13"?

 

[trailpsycho]

What kind of clearance do you have with the tranny and tunnel cover. I know you said you have the NV3550 and WH 1" BL...but with the Extreme Mounts up front, you are raising the front of the drivetrain quite a bit. MY thinking is to put a shim between the tranny and tranny mount (should be plenty of thread there is I remember correctly). And if your front is raised there is probably room at the back (tunnel area) to shim at the tranny/mount. Just be aware that the overall extra height (1/2" or so is eating into your body lift, so additional shims in the body lift may also be necessary.

I have done this on my NV4500 install b/c of the steep angle I found in my drivetrain once the body was back on. I had a spare piece of 1/2" plate that was just as wide as the AA crossmember, so I drilled it to match and put it in between the tranny mount and crossmember. I also had to add 1/2" UHMW discs and washers between the WH 1" body mount and the body...but that wasnt a big deal, I was able to reuse most of the hardware (or rotate it to another mount). Just trying to give you some ideas...

The idea is that by raising the back of the drivetrain, you will decrease that angle of bind at the front of the D20. And it shouldnt take a whole lot. I havent figured out my drivelines yet...soon. One step at a time.

 

[cgbexec]

I just talked with Jeff's Bronco Graveyard and we think that I have the 5.5" springs which may be causing my problem. They don't have a compressed figure for the 3.5" springs, but he is going to get that number and we will check it against my figure of 18.5" compressed. Dropping the front suspension 2" would definately illiminate the bind. I am not sure what would happen at full droop, but I may be able to lower the engine 1" which as you pointed out may lessen the angle at the transfer case. I think that we are getting closer to a solution.

Thanks for all of the help.

Chris B.

 

[NYLES]

I been reading and lookin.....I noticed in your pics...to me looks like your transcase yoke is angled upwards.....you say your engine is an inch higher...which would increase the angle at the transfer .....you could also riase the transfer to match the engine....look at your x member to insure everything is installed correctly that can affect the angle.....i know on stock x member one bushing is almost twice as thick as the other..and installed backwards would cause some of your angle problem.....just a thought

Could be facing more than one gremlin here!

dropping the engine down 1" will help for sure...how did you end up an inch higher?

 

[cgbexec]

The NV3550 tranmission comes with a new transmission crossmember. I tripple checked it against the directions and the pictures. There is only one large rubber mount and it is installed correctly. In fact if you flipped over the other way, it would raise the transmission up about 3 inches and that would make the engine sit nose down. I know that is not correct. The new engine mounts are very nice. Now that the engine has been sitting on them for about 3 months, I am going to loosen the bolts and see if I can get the engine to drop down just a little bit. The harmonic balancer is about 2.5" above the cross member. It could certainly come down a little with no trouble.

 

[NYLES]

Will it fit flipped over? and let me know if the engine drops down after you loosen the mounts.....x mission may in fact be too low forcing the engine into a nose up postion and if you were to flip the bushing it would raise the xcase and lower the engine...id loosen motor mounts and flip it just to see the results....you might like em! if engine goes down and xey goes up and all still bolts up ....problem solved.

comparing my pics and yours I say x needs to come up! grated mines a c4 look at pics in my gallery....

Did you do dremal work on outside of CV at transfer? if so why? what was it hitting?

 

[cgbexec]

When I got home I did some measuring. I am now very sure that I have the wrong springs. Here is what I got.

14-1/4" Top of axel to bottom of frame above

18-1/2" Compressed spring height

The difference from the rear bumper to floor and the front bumper to the floor is 6". In other words the front bumper is 6 inches higher than the rear bumper.

I bought two 1000 lb. working capacity ratchet straps on the way home today. I went around the frame and around the axel, one on each side. I cranked them as tight I dared to. They were piano wire tight. The height from the top of the axel to the bottom of the frame was 12". So basically I was able to compress the front suspension 2-1/4". I then measured the bumpers and now the front bumper was only 2 inches higher than the rear. This tells me that I definately have the wrong front springs. I did not install the front drive shaft, but the angle was definately less severe and looked like it was workable. Tomorrow I call Jeff's Bronco Graveyard and tell them the bad news.

I also loosened the motor mounts and got the engine as low as possible. It only dropped about 1/2 inch at the most. The bolts are now bottomed out in the engine frame supports, so the engine can go no lower.

Thanks,

Chris B.

 

[KRAWLER]

That is alot of angle, I got to agree with chuck. The bushing should for the most part take that angle that you have out. I've got a 5.5" duff lift with Duff C Bushings and I sit pretty straight compared to yours.

 

[bigmuddy]

On my rig, I have 2 degree bushing with the Cage arms, the cage arms have 4.25 built in if memory serves. But it just dawned on me that when I installed the ZF tranny I rotated the D-20 all the way up and that coupled with the extreme motor mount caused most of the binding.

Ben

 

[trailpsycho]

The NV3550 tranmission comes with a new transmission crossmember. I tripple checked it against the directions and the pictures. There is only one large rubber mount and it is installed correctly. In fact if you flipped over the other way, it would raise the transmission up about 3 inches and that would make the engine sit nose down. I know that is not correct. The new engine mounts are very nice. Now that the engine has been sitting on them for about 3 months, I am going to loosen the bolts and see if I can get the engine to drop down just a little bit. The harmonic balancer is about 2.5" above the cross member. It could certainly come down a little with no trouble.

I am very familiar with the NV3550. I have installed one before. I have no doubt that you installed the kit per the AA instructions, but the AA kit doesnt account for your higher mounted engine due to the aftermarket engine mounts. What I am saying is that with your aftermarket engine mounts (that sit higher than stock--remember, the AA kit was designed for stock applications), that the engine is still higher than what the kit was designed for, therefore with the kit installed as directed by AA your tranny/transfercase are sitting lower at the back than what the kit was designed for. This increase in height at the front results in a 'negative' driveline angle for the front driveline b/c the TC is pitched slightly rearward. Do you follow? By adding a shim (1/2" plate or whatever you have room for--due to body and tunnel clearance) between the tranny crossmember and the rubber tranny mount (that bolts to the transmission), you will (begine to) effectively level out the drivetrain and reduce your 'negative' angle at the front TC yoke.

While you may have received the wrong springs and that is contributing to your problem, it sounds like you may still have issues with the 3.5" coils. I hope that is not the case and another set of coils reduces your bind problem. If not, you have my advice above.

 

[NYLES]

Trailpsycho.....you make that much more understandable but I get ya!

Just what if hes got the wrong rear springs? would that not cause the same bad tcase angle? just something else to look at.

 

[cgbexec]

The rear springs would have no effect on the front drive train angle. It would effect the rear angle.

I agree that a shim under the transmission would help with some of the angle, but at this point the 5.5" lift on the front and 3.5 in the rear is my main problem at the moment. Once I get the 3.5" springs in place and they settle, then I will install the driveshaft and see what I have. If I still have a problem, then I will see how much shim I can use.

Thanks,

Chris B.

 

[NYLES]

nope problem is the 5.5's.....3.5 rears are ok!

I think you got it figured out!...sucks waiting on new springs.

 

[cgbexec]

I just got off the phone with JBGY. They called me back as promised with information. This is what I found out.

The fabritech Radius Arms (a thing of beauty) add 1.5" of lift by themselves. I did not know this.

They are sending me 2.5" front springs. That will actually give me 4" of total lift in the front. At this point I think I have the 5.5 springs and 1.5" of lift in the front for a total of 7" of lift. That may explain why my front bumper is 6" higher than the rear and the drive shaft is binding at rest.

They are sending me 1" wedges for the rear springs. This should level out the package and give me a slightly better rear pinion angle.

So the moral of the story is that if you buy Fabritech Radius Arms, they have a built-in 1.5" of lift.

Jeff's Bronco Graveyard has been good about this. They are shipping the parts out now and told me that when I have the old springs out to call them for a U.P.S. pickup.

This has been a learning expierience!

Chris B.

 

[NYLES]

I knew there was another GREMLIN in there some where! good info on the arms...