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-   -   mml questions (http://www.wranglerforum.com/f282/mml-questions-234607.html)

98 tj sport 04-11-2013 01:00 PM

mml questions
 
Ok so I put an advance adapters sye and tom woods on the jeep last week, I took the transfer case drop out just to c how far the pinion angle was off, and to my surprise it is almost right, so I left it out to c how it rode, I get a very slight and I mean slight vibe I didn't even notice it at first, my question is would puttin in a mml and a couple of washers between the frame and skidplate most likely take care of this problem, I just don't wanna have to put that giagantic drop back in cuz it looks better and I have more clearance, ik I can do adjustable uppers to fix it but if a mml and a couple washers will fix it as well, that is a much cheaper fix and I would rather do that thanks

homebrwd 04-11-2013 01:03 PM

No, you NEED adjustable uppers, you have to change the angle of the differential pinion and point it at the transfercase output.

blkrubi88 04-11-2013 01:08 PM

It should help, plus it gives you the option to install a high clearance skid later on for more ground clearance.

homebrwd 04-11-2013 01:36 PM

Quote:

Originally Posted by blkrubi88 (Post 3623875)
It should help, plus it gives you the option to install a high clearance skid later on for more ground clearance.

He has an SYE and driveshaft, the point of the MML with a tummy tuck is to help driveline angles because the transfercase output and rear diff pinion need to be parallel. Since that is not the case with a DC shaft a MML will not help him with a tummy tuck skid.

OP, again, you are better off getting the upper adjustables. Its the better solution to your problem. I'm not sure a MML would really help since it really doesnt change the angle of the output that much with an SYE since the pivot point of the drivetrain is the transmission mount on the skid, raising the engine 1in only lowers the TC output 1/3 -1/2 inch if that. The drop would still be needed.

blkrubi88 04-11-2013 01:43 PM

Quote:

Originally Posted by homebrwd (Post 3623978)
He has an SYE and driveshaft, the point of the MML with a tummy tuck is to help driveline angles

And better drive line angles helps reduce drive line vibes, he said he had very little vibes.

homebrwd 04-11-2013 02:48 PM

Quote:

Originally Posted by blkrubi88 (Post 3624007)
And better drive line angles helps reduce drive line vibes, he said he had very little vibes.

It doesnt help driveline angles with an SYE. The angles are setup differently between a slip yoke and an sye.

http://www.4xshaft.com/images/2joint_angle.gif
With a slip yoke and non DC shaft you have have the the transfer case output and diff pinion on the same plane ie the same angle. The reason a MML helps with a tummy tuck is because it brings the transfercase angle back to parallel with the pinion. This is also the reason for a transfercase lowering kit with tall lifts, instead of the slight change an MML gives the lowering kits generally drops the output shaft about an inch or a little more.

http://www.4xshaft.com/images/cv_angle.gif
With an SYE and DC shaft that is not the case any longer. The pinion needs to be pointed at the output shaft of the transfercase in this situation. His driveline vibes are because that is not what is happening. Considering he probably has either fixed length arms skyjacker, or still the stock arms, his pinion angle on the diff is off and needs to be fixed. The MML will do him no good and would be a waste it would barely lower the output shaft inline with the pinion (the tcase drop would still need to be in place), put the spacers back in until you can get new arms.

OP can you take a picture of the rear driveshaft with the transfercase and diff in it as well?

98 tj sport 04-11-2013 04:50 PM

2 Attachment(s)
Sure thing this is the best I could get

Attachment 234891



Attachment 234892

All Terrain TJ 04-11-2013 05:15 PM

Can't type much now but your pinion needs to come up.

1320quick 04-11-2013 06:27 PM

Quote:

Originally Posted by All Terrain TJ (Post 3624806)
Can't type much now but your pinion needs to come up.

Yep. It should probably look more like this.

http://i212.photobucket.com/albums/c...ps54cafc9c.jpg

Using the rear upper adjustable control arms will be your best bet for setting it up correctly.

cchartrand 04-11-2013 06:48 PM

Quote:

Originally Posted by homebrwd

It doesnt help driveline angles with an SYE. The angles are setup differently between a slip yoke and an sye.

With a slip yoke and non DC shaft you have have the the transfer case output and diff pinion on the same plane ie the same angle. The reason a MML helps with a tummy tuck is because it brings the transfercase angle back to parallel with the pinion. This is also the reason for a transfercase lowering kit with tall lifts, instead of the slight change an MML gives the lowering kits generally drops the output shaft about an inch or a little more.

With an SYE and DC shaft that is not the case any longer. The pinion needs to be pointed at the output shaft of the transfercase in this situation. His driveline vibes are because that is not what is happening. Considering he probably has either fixed length arms skyjacker, or still the stock arms, his pinion angle on the diff is off and needs to be fixed. The MML will do him no good and would be a waste it would barely lower the output shaft inline with the pinion (the tcase drop would still need to be in place), put the spacers back in until you can get new arms.

OP can you take a picture of the rear driveshaft with the transfercase and diff in it as well?

Nice explanation my friend! W/ illustrations! Great that fellow Jeepers take the time to explain things clearly, and w/ out being snarky. Well done.

98 tj sport 04-11-2013 10:53 PM

Quote:

Originally Posted by 1320quick (Post 3625082)

Yep. It should probably look more like this.



Using the rear upper adjustable control arms will be your best bet for setting it up correctly.

aside from the fact of thanks for the pic, I must say that is one clean underside that u have there, wish I could get mine that clean

98 tj sport 04-11-2013 10:55 PM

And thanks for all the replies looks like ill just get some arms


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