International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 08-03-2020, 10:19 PM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 123
Driveline noise

I have a 72 j4000 that I bought with a 2wd Chevy driveline. Since it ran well, I had my friend install a divorced Dana 20, custom cross member and driveshafts.
It starts up, runs well, shifts in and out of 4wd but has a bad driveline noise that gets worse as rpms increase. Sounds like a whining noise and maybe a friction type noise. It actually caused a vibration when up on lift, but no vibration when on ground.
When we had it up on lift, in gear, it seemed like vibration was coming from transfer case.
I bought another Dana 20 and still same issue.
I'm thinking maybe the short shaft from trans to transfer case is at a bad angle or something with the divorced adapter isn't quite right. Don't want to keep wasting money guessing.
What do you guys think?
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels

Last edited by brentwood : 08-03-2020 at 10:27 PM.
Reply With Quote
  #2  
Old 08-04-2020, 02:50 PM
J20 project's Avatar
J20 project J20 project is offline
304 AMC
 
Join Date: Dec 27, 2000
Location: Nevada
Posts: 2,377
Hmm, while I really have no doubt that if that unit was in my care.....I could figure it out. But 2 things stand out. 1) I have never seen a divorced Spicer(Jeep ) 20, much less 2 of them.. so interesting at least. 2) divorced cases are typically set up in line...straight, no angles and if that is what you have welllllll good luck, and maybe your ace mech is not so ace........3) oops 3...did you have quality driveshafts built or some redneck "it'll work" junk.....?



Actually trying to help, but I do that by challenging peoples' thought processes.....

J20....I build shafts and drivelines for a living,,,,been wrenching on these es for 45 years....
__________________
BP Drivetrain...........

Driveshafts for all Jeeps, Constant velocity rebuilds, Replacement, Repair
775-537-7918

https://www.facebook.com/BPShafts/
Reply With Quote
  #3  
Old 08-04-2020, 05:02 PM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 123
Quote:
Originally Posted by J20 project
Hmm, while I really have no doubt that if that unit was in my care.....I could figure it out. But 2 things stand out. 1) I have never seen a divorced Spicer(Jeep ) 20, much less 2 of them.. so interesting at least. 2) divorced cases are typically set up in line...straight, no angles and if that is what you have welllllll good luck, and maybe your ace mech is not so ace........3) oops 3...did you have quality driveshafts built or some redneck "it'll work" junk.....?



Actually trying to help, but I do that by challenging peoples' thought processes.....

J20....I build shafts and drivelines for a living,,,,been wrenching on these es for 45 years....


1. The original used Dana 20 I bought came with a divorce adapter already installed. Novak and some other companies made divorce kits for the Dana 20s. So I used the same divorce kit with the 2nd Dana 20.

2. Nobody said my friend is an ace mechanic and he doesn't own a driveshaft shop if that's what you're getting at.
The short shaft is centered width wise under truck, but a little off height wise. Would a double cardan joint help this?

3. He set it up so front and rear driveshafts are the same length. He made one, and the other was made by professional shop. It made no difference with issue which one was in rear.

4. So should I be looking into the divorce adapter or the short shaft (trans to case)? Or something else I'm missing?
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #4  
Old 08-05-2020, 11:38 AM
J20 project's Avatar
J20 project J20 project is offline
304 AMC
 
Join Date: Dec 27, 2000
Location: Nevada
Posts: 2,377
Actually, assuming you have a short shaft th400...which your truck would have had if auto when new.....I would just go back to oem configuration and bolt the tcase to the trans....
I know that would be reversing a lot of work but...

Also, what does your intermediate coupling/shaft look like? Most boats, etc will have a pair of 1310 type flanges bolted together...

Lastly, if the truck cruised w/ a single shaft in the rear okay, and the rear shaft professionally done...the issue is likely as you said,,,well sorta. The issue lives between the ouput of the trans and the ouput of the tcase, right?


J20.
__________________
BP Drivetrain...........

Driveshafts for all Jeeps, Constant velocity rebuilds, Replacement, Repair
775-537-7918

https://www.facebook.com/BPShafts/
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Driveline Schooling Needed. D300 to D44s JoggerFogger General FSJ Tech 33 11-16-2017 09:34 AM
Engine noise, 4.0 swap???? Mex in the city General FSJ Tech 5 11-24-2008 04:00 PM
GW - Loud noise.... like a groan or a rubbing? cate General FSJ Tech 4 09-27-2007 10:26 AM
Simple diagnosis of odd driveline noise - a Tip! Manhattan General FSJ Tech 2 07-24-2003 02:32 AM
test driveline noise problem miked General FSJ Tech 3 04-13-2001 04:09 AM


All times are GMT -6. The time now is 10:08 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
corner corner