View Full Version : T-case clocking question
Jeff 98XJ WI
April 25th, 2005, 18:19
Ok, lets not get into the why do you want to do that. Instead, lets get into will this work, ok? I am considering redrilling the AW4 output housing to clock the t-case up a little. However, I can't go much. So, how close to each other can the holes be? Is there any reason I can't drill a new pattern offset from the stock one with the resulting holes having something like 1/16" of material between them? If needed, I could probably tap the stock set of holes and thread in an allen head plug to fill the holes. The holes do NOT need to be sealed or anything, my main concern is whether or not the holes can be spaced closely and not cause any sort of problem. I think it can be done, but I would like to hear your thoughts on whether or not it is a good idea. Jeff
Jeff 98XJ WI
May 2nd, 2005, 09:08
It's interesting that this thread got NO responses. So, I guess I'll respond myself. I completed the transfer case clocking project in my '98 this weekend. After pulling the t-case and AW4 output housing adapter, I found the holes in the adapter to be just a hair over 7/16". However, I couldn't find ANY 7/16" aluminum dowel material in my little town and I didn't want to wait, so I had my buddy turn down a piece of 3/4" or so aluminum rod that I found at a used steel place. He made it a tight fit that required pressing/hammering the plugs in place. I mixed up some jb weld and coated the holes and dowels with this prior to installing them in the holes, but I'm not sure if any stayed in there. After letting the jb sit all night, I used a sanding wheel on my grinder and touched the dowels up till they were flat against the housing on both sides. Holes filled!!! I then scribed a line around the center line of the bolt holes while the housing was sitting on the AW4 tranny by using a compass in the center of the output shaft and then layed out the new hole positions about 5/16" off from the old holes which should raise the front output shaft of the transfer case about 7/8". I figured this number by setting the housing on some cardboard, tracing the bolt holes, finding center, and then using a square to draw a line from the center of the housing, through the center of one bolt hole, and then off to a 90 degree from the center of the bolt hole. 9.5" out (distance between center lines of the t-case output shafts), I measured up 7/8" as that is the magic number for the desired front output rise. Then, I used the square on the new mark and worked back to the new center line of the new hole on the adapter housing. Turns out that the new holes will overlap the old holes about 1/16" or so. Anyway, after centermarking the new hole locations, I simply drilled them out in steps on the drill press. Worked like a charm. Here is an album with a bunch of pictures: http://share.shutterfly.com/osi.jsp?i=EeEN2jZq0btmGu
Jeff
rstarch345
May 2nd, 2005, 09:23
Jeff, I find this interesting.
If I follow the reasoning for you doing this, you did a great job.
I was looking at my T-case and was wondering if it couldn't be rotated. It's a great way to realign the pinion angles and leveling out the T-case. I like it.
Other than the time for the JB Weld to set up, I'm guessing you have about 5 or 6 hours of actual work in the project?
I'm presuming you have everything back together? How has it worked out?
Againg, very nice job.
XJ_ranger
May 2nd, 2005, 09:26
nifty...
though im not sure i like the overlap into the old holes that are capped with JB weld...
how much would it cost to get a machineist to tig thoes dowels in for you?
i might get into taking my ax-15 apart someday, but till then - mine will be clocked the same...
Jeff 98XJ WI
May 2nd, 2005, 09:40
I did have some discussion on a different email list about how to plug the holes and there was some concern over warping with welding. One guy suggested an interference fit with heating the housing and cooling the dowels and then after the dowels were in place and the temps equalized, they would be in there permanently. I probably could have done that with these dowels because it took some hammering to get them in and I think I may have pushed out pretty much all the JB weld anyway. The point is that the dowels are in tight and drilling the new holes didn't disturb them at all, so once the nuts are on the t-case studs, there's no place for the dowels to go even if they did work loose! I have all the confidence in the world that the rotated mounting position will work fine with NO problems. I'm not so sure about the rest of the hidden long arm project though. :) Oh, I don't have it back together yet either. That's tonights project...since I have to drive it to work tomorrow! Wife wants her car back. :) Jeff
nifty...
though im not sure i like the overlap into the old holes that are capped with JB weld...
how much would it cost to get a machineist to tig thoes dowels in for you?
i might get into taking my ax-15 apart someday, but till then - mine will be clocked the same...
RCP Phx
May 2nd, 2005, 16:38
What about the increased angle on the front driveshaft,its already bad enough?
Jeff 98XJ WI
May 3rd, 2005, 06:38
What about the increased angle on the front driveshaft,its already bad enough?
Yeah, that is a bit of an issue. However, I only raised the front output 7/8" or so based on my calculations and that's not that much. Also, Crash and Jes are successfully running similar angles, so I figure if they can, so can I. :) I'm running a hp d44 too, so the shaft won't be spinning unless the hubs are locked. It's all about clearance you know! Jeff
ChuckD
May 3rd, 2005, 07:18
What about the increased angle on the front driveshaft,its already bad enough?
WOW, no !!! !!! !!!
Did you get some therapy? :D
Clean Racing
May 3rd, 2005, 08:05
Ok. am I the only one thinking about the pick up for the oil pump??? how far up do think it would take to starve the oil pump?? Since the pick up screen is in the bottom of the case in the very same area you are raising up. Have you thought about how much more fluid you will need to run to avoid starving you t-case of lubrication... I am not trying to be a downer, but the t-case only has a little over a quart and half of fluid to operate on... just my .02$ worth.
Jeff 98XJ WI
May 3rd, 2005, 08:28
Ok. am I the only one thinking about the pick up for the oil pump??? how far up do think it would take to starve the oil pump?? Since the pick up screen is in the bottom of the case in the very same area you are raising up. Have you thought about how much more fluid you will need to run to avoid starving you t-case of lubrication... I am not trying to be a downer, but the t-case only has a little over a quart and half of fluid to operate on... just my .02$ worth.
I don't think that will be a problem. TJ's with the 231 have it clocked MORE than I just did. Owners of TJ's that install AW4 trannys clock the t-case just like I did, but MORE than I did. Jeff
http://www.stu-offroad.com/engine/aw4/reclock.htm
JeepFreak21
August 31st, 2008, 08:35
Hey Jeff,
Blast from the past!
Did this continue to work well for you (up until you pulled the 231, I mean)?
Would you do it again the same way?
Anybody know if there are better (but still dirt cheap) solutions out there now-a-days?
Billy
WI88XJ
August 31st, 2008, 09:47
Well, Billy, I guess I can step up and answer that for you. I bought that '98 from Jeff last year and it still has the 231 in it. It's been no problem what so ever and still going strong. It's nice to have a flat belly and not hang up on everything like my other rig. I drive this to all my wheeling trips and then wheel the pee out of it. It will be at the WOHVA run at Dresser the end of September and the Fall Color Run at McCaslin, the Toy run at the Badlands and maybe Winterfest if I'm not broke by then ($'s).
http://i74.photobucket.com/albums/i245/OldBlueBeater/Misc%20pics/doublebump.jpg?t=1220201150
JeepFreak21
August 31st, 2008, 09:53
Well, Billy, I guess I can step up and answer that for you. I bought that '98 from Jeff last year and it still has the 231 in it. It's been no problem what so ever and still going strong. It's nice to have a flat belly and not hang up on everything like my other rig. I drive this to all my wheeling trips and then wheel the pee out of it. It will be at the WOHVA run at Dresser the end of September and the Fall Color Run at McCaslin, the Toy run at the Badlands and maybe Winterfest if I'm not broke by then ($'s).
http://i74.photobucket.com/albums/i245/OldBlueBeater/Misc%20pics/doublebump.jpg?t=1220201150
Great news! Thanks Steve,
Billy
WI88XJ
August 31st, 2008, 12:06
I couldn't post these before 'cause momma had me run an errand, but...
check these two out for further reference:
http://i74.photobucket.com/albums/i245/OldBlueBeater/Misc%20pics/IMG_1739.jpg?t=1220209438
http://i74.photobucket.com/albums/i245/OldBlueBeater/Misc%20pics/IMG_1740.jpg?t=1220209486
Other than mud and surface rust still rock solid.
xjjeeper19
August 31st, 2008, 20:20
Look at it this way, on a wrangler, it's already clocked that much fron the factory. I found this out the hard way when I put an NV3550 in my jeep, I had to re-drill the holes and clock it down because I was not in the mood to cut the floor.
Justin
Jeff 98XJ WI
September 5th, 2008, 10:49
Well, Billy, I guess I can step up and answer that for you. I bought that '98 from Jeff last year and it still has the 231 in it. It's been no problem what so ever and still going strong. It's nice to have a flat belly and not hang up on everything like my other rig. I drive this to all my wheeling trips and then wheel the pee out of it. It will be at the WOHVA run at Dresser the end of September and the Fall Color Run at McCaslin, the Toy run at the Badlands and maybe Winterfest if I'm not broke by then ($'s).
http://i74.photobucket.com/albums/i245/OldBlueBeater/Misc%20pics/doublebump.jpg?t=1220201150
Damn I miss my rig! :( Good to see it out crawling around though. :) If I wanted to clock a 231 again, I would not hesitate to do it the same exact way. Jeff
whitneyj
September 8th, 2008, 19:11
So here's a question. . . to fill those holes why didn't you put a bolt with green loctite in it? to slack tolerances? I'm looking to do the same thing you did, but don't want to source the AL dowels around here. . . PRICEY. ..
Jeff 98XJ WI
September 9th, 2008, 20:04
Since I wanted to drill the new hole half way in the old hole I think trying to drill half a bolt and half aluminum would be hard. If the new holes could be drilled it would work just fine I think. Jeff
Mr_Random
September 9th, 2008, 20:21
so the t-case hump of the xj accommodates this clocking? under torque did it tap the floor? What about the lever brackets? I suppose an aftermarket shifter would still work... but yeah, I like questions!
JeepFreak21
September 9th, 2008, 21:47
so the t-case hump of the xj accommodates this clocking? under torque did it tap the floor? ...
I went quite a bit farther than Jeff did, so I'll let you know in a couple days when I get the t-case installed! I anticipate having to give the floor some love with the BFH though. :D
Billy
JeepFreak21
September 9th, 2008, 21:48
So here's a question. . . to fill those holes why didn't you put a bolt with green loctite in it? to slack tolerances? I'm looking to do the same thing you did, but don't want to source the AL dowels around here. . . PRICEY. ..
Become a supporting member and I'll ship you my left overs for free ;)
Billy
whitneyj
September 10th, 2008, 03:55
guess what I'm doing after work today. . . :)
JeepFreak21
September 10th, 2008, 08:04
guess what I'm doing after work today. . . :)
PM me your addy when you're done :cheers:
Billy
JeepFreak21
September 14th, 2008, 14:13
I got my write-up done.
http://www.bsfab.net/?p=23
Billy
PS - I shipped your stuff WhitneyJ. :cheers:
whitneyj
September 14th, 2008, 14:35
Awesome write up, I like your method of measuring the distance of the new holes a little better. I was worried about using a compass like Jeff98XJWI did, the way things tend to end up with me I need less room for error. :) With 10* of rotation you're not worried about starving the tcase for oil? I know the TJ's are clocked something like 10* more than the XJ, not sure how much though. . .
ps thanks for the plugs, I appreciate it!
JeepFreak21
September 14th, 2008, 14:59
Awesome write up, I like your method of measuring the distance of the new holes a little better. I was worried about using a compass like Jeff98XJWI did, the way things tend to end up with me I need less room for error. :) With 10* of rotation you're not worried about starving the tcase for oil? I know the TJ's are clocked something like 10* more than the XJ, not sure how much though. . .
ps thanks for the plugs, I appreciate it!
Nah, I'm not worried about the oiling... I'm looking for a reason to buy an Atlas! :D
Actually, yeah, because the TJ's are already clocked up about the same, and because I found a few other XJ guys that have had good results with a similar amount of rotation (CRASH), I think it'll be fine.
Billy
Deadwood
September 15th, 2009, 13:45
OK - gonna bring this old thread back.
I'm thinking of doing this when I add a SYE. Those that have done it - Issues? Problems?
I guess I'm concerned about front DS angle and additional mods that I might have to do after the TC gets clocked.
I have a '97 XJ with AW4, NP231, looking at 3" lift (4"max).
I also like the possiblility of grabbing a TJ?? or YJ?? transmission housing from the JY that may not need to be redrilled?? since they are already clocked somewhat compared to the XJ? If that wouldn't work I'd consider grabbing an XJ housing and redrilling it to reduce the downtime on my DD XJ.
Any insight is appreciated.
PS - thanks Billy (JeepFreak21) for your insight.
RCP Phx
September 15th, 2009, 13:47
The t-cases are all clocked the same,its the transmission adapter thats different!
Deadwood
September 15th, 2009, 13:50
Does that mean that I could take the transmission adapter from a TJ or YJ and effectively get the same effect? I realized I haven't crawled under a TJ or YJ to look at things myself - but I will - especially if there's any indication that it would work.
MG2000XJ
September 15th, 2009, 14:29
Great writeup, definitely on my to do list along with new bellypan.
JeepFreak21
September 15th, 2009, 14:39
The t-cases are all clocked the same,its the transmission adapter thats different!
What's your point? http://www.slicky.net/smilies/dunno.gif
Billy
anthrax323
September 15th, 2009, 16:13
Does that mean that I could take the transmission adapter from a TJ or YJ and effectively get the same effect? I realized I haven't crawled under a TJ or YJ to look at things myself - but I will - especially if there's any indication that it would work.
I, too, am extremely interested in this (as well as whether or not it'd mate with a 242).
RCP Phx
September 15th, 2009, 16:39
Does that mean that I could take the transmission adapter from a TJ or YJ and effectively get the same effect? I realized I haven't crawled under a TJ or YJ to look at things myself - but I will - especially if there's any indication that it would work.
They dont use the AW-4,not sure about the manuals!
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