Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Labrat0013 on April 13, 2012, 09:41:30 PM
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Hey guys,
Looking for some help. I have a 2" lift on my tj. 4.0 l 5 spd trans d35 rear. My output shaft angle is 10*, drive shaft is 19* and pinion is 16*. i figure i need to either drop my t case or raise my mount. I think a 1" mml might be too much. Any idea how much i would need to drop my t case to line these angles up better? Should i be measuring/adjusting my angles with a full tank and with some weight or almost empty tank and no extra weight? I want to make sure i am not throwing off my angles when towing my trailer.
Cheers,
Cris
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i can't help you other than to suggest do not drop the skid plate. Someone else will chime in on how to accomplish what you want without dropping the skid. 8)
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Hey guys,
Looking for some help. I have a 2" lift on my tj. 4.0 l 5 spd trans d35 rear. My output shaft angle is 10*, drive shaft is 19* and pinion is 16*. i figure i need to either drop my t case or raise my mount. I think a 1" mml might be too much. Any idea how much i would need to drop my t case to line these angles up better? Should i be measuring/adjusting my angles with a full tank and with some weight or almost empty tank and no extra weight? I want to make sure i am not throwing off my angles when towing my trailer.
Cheers,
Cris
I am slightly confused as to where you are measuring these angles and what you are using as reference. Output shaft angle? Can you take a picture of how it's looking right now?
With a 2" lift you should be changing the angle enough to worry about your u-joints, you can go up to 3" without trouble. 4" is iffy and sometimes requires a SYE to lengthen the drive shaft and get the angle better. Adjustable control arms can sometimes help your pinion angle too.
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The angles i have mentioned are in relation to the ground, my garage floor is not exactly level so they may be off a bit. The out put shaft angle i have measured off of the transfer case itself (flat portion around the output shaft) the drive shaft angle is self explanitory and i measured the pinion angle from the flat portion on the back side of the diff. I understand that in most caes a 2" lift does not affect the angles enought to cause issues but i have considerable vibration. I installed a temporary t case drop with washers to see if it made a difference (slightly less than 1/2" drop). Angles now at output shaft 13* drive shaft 21* pionion 18* once again relative to ground (measurements taken on slight slope) It did improve the vibrations but i still have some at highway speeds. In know ideally the t case output shaft and the pinion should be at the same angel with a 3* max difference between these and the drive shaft angle. Im thinking a 1" mml would work best, can i do this without a body lift? I am ok with a t case drop as well as i am not overly concerned about the 1" clearance. Which choice do you recommend, keep in mind i am trying to keep costs down (hence the budget boost).
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The objective is to get them as equal as possible. Regardless of the angles, if they aren't equal, it won't balance.
Regardless, less is always better.
According to your numbers right now you have 8 degrees on the output and 3 at the pinion.
8 degrees is to much. Absolute max is maybe 7, recommended is about 5.
You would be better off running a mml then not in this situation. A mml will only buy you about 2-3 degrees.
You will still be slightly uneven but better then where you are now.
Ideal would be he exact same number on both joints.
For instance 12-16-12. Meaning each joint has an operating angle of 4 degrees.
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Thanks Bill,
Any idiea if i will be able to install a MML without a Body lift? Will me engine/body clearance be enough aferwards?
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Yup. Common mod is mml without bl. It fits. Gotta raise the fan shroud though.
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What is the most you can lift a motor?
2003 TJ Sahara, 4.0 -5 speed.
(I already have a 1" mml)
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1" mml is all I have ever seen, I assume anything more than 1" is a bad idea or is impractical...otherwise they would probably make it to help people avoid the cost of a sye etc etc
Are you experiencing vibration? if not I wouldn't touch it. The proper way to do this is A Sye kit + a new CV drive shaft + adj rear uppers. If you don't know what this is google it 8)
Maybe just a set of rear uppers will work for your application? Adjustable rear upper control arms allow you to point the pinion higher to get adjust-ability in your angles. They could give you enough adjustability to solve your issue
IMHO- Drop the T-case and make life easy until you can do it right, just add some washers under the bolts until your angles are good. Maybe buy some longer 10.8/ grade 8 bolts from greggs if you need to. I have my old T-case drop, bolts and spacers from my bds 3", it might be a bit aggressive for your purposes though....Even with a T-case drop there is just no substitute for how much smoother the jeep will be with a CV shaft installed, at least that way my experience
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So i have been messing around with t-case drops to see what it is going to take to get my driveline angles right. So far I have the t-case down 1" and now have angles as follows; output 12* drive shat 11* pinion 15* (fuel tank full). So from what i can see i will still need some t-case drop along with my 1" mml to get things aligned without new contorl arms (one thing at a time).
Any recommendations on motor mount lifts? Ive read that the M.o.r.e mounts are strong and won't transfer vibes like the jks. Or should i just go with stock mount lifts?
Thanks again!
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For some reason I thought you already had a mml....
The older the jeep the more inclined I would be to go with a full replacement, MORE is a good name for sure, I'd probably splurge and go that route over the poly or whatever.
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Brown Dog, mine was about 100$ to the door, its also a full replacement, not just a spacer block. However if you are having that much of an issue, order some adjustable uppers like others have said. Iron Rock Offroad has some pretty inexpensive ones.
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I have the MORE ones on my YJ and I would recommend those
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What is the most you can lift a motor?
2003 TJ Sahara, 4.0 -5 speed.
(I already have a 1" mml)
You can do 2" if you want. Its easy to couple a lift block with an aftermarket mount for a combined 2". But you definately need some body lift at that point.
I run 2" of mml in my rig.
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I run 2" of mml in my rig.
In the YJ?? ?? ?? ???
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No the TJ
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So I installed my 1" motor mount lift. I now have the following angles with
Both the 1" mml and the 1" t-case drop. Output 10* drive shaft 5* pinion 10*. So my next question is, do you recommend leaving everything as is or raise my t case to reduce the pinion/driveshaft and driveshaft/output angles and sacrface a bit of the output/pinion pairing? Keep in mind these angles are measured with a half tank. If i hook up my tent trailer with the current set up this would drop the rearn end making the drive shaft flatter and the pinion/drivesahft and driveshaft/output angles greater than 5*.
Any thoughts?
Cheers,
Cris