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Unread 03-26-2008, 06:37 PM   #1
bjmilz
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88MJ Tranny Problem

I am brand new to this forum and in need of some help. I have an 88 4.0 Comanche 4x4 with 154,000 miles. Recently my tranny started acting up. It is nearly impossible to shift into 1st or 2nd while moving. When I upshift into 4th it grinds a bit (now I am shifting from 3rd, touch 5th, and then 4th). When I am in reverse it is almost like the brake is on every rotation of the shaft. Also, when the clutch is disengaged and in neutral (like at a stop light) I get some vibration. This vibration goes away when I shift the transfer case into neutral (obviously).

I am thinking the synch is messed up, but I do not know what to do. I am thinking about getting another tranny, but I would like to see what advice any of you have.

I appreciate the help!

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Unread 03-26-2008, 09:01 PM   #2
Pete M
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The first thing I would do is make sure the gear oil is topped off. I had all sorts of weird issues like that when the fluid level dropped in my 88. Your transmission is the ba-10/5 (made by Peugeot) and is notorious for giving the owner headaches. You may want to start looking into the AX-15 swap so you'll be prepared if the trans is dying. Whatever you do, do NOT try to rebuild a Peugeot. The parts are insanely expensive and the trans will likely fail again in short order. It's not a very good transmission.
Good links:
http://www.jeeptech.com/convtrans/ax15swap.html
comancheclub.com/forums
Jeep on!
--Pete
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-88 MJ; 4.0L, ex-2wd, TJ ax15/231, 78 Ford D44 w/spool, 9" w/posi, 33" trXus MTs, custom roll-bar/bumpers/etc.
Also an 86 MJ Metric ton and 2 '90 MJs
Projects/wheelin' pics: picturetrail.com/petermontie
My email: petermontie@hotmail.com
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Unread 03-27-2008, 09:36 AM   #3
75SV1
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I will agree with Pete. Some have had good luck with their Peugeouts. Mine was starting to grind on the 3/4 shift. I think the syncros are $200 to $300 each. One on the 1/2 shift and another on the 3/4 and probably one on the 5th. None on reverse. The AX-15 is probably the most cost effective. The NV 3550 with also work. I'd give you my Peugeout to get it out of the garage. The price for an AX-15 should be about $400-$800. I'd try and get a latter one (95? or 96+) with the external slave cylinder. I didn't read the article very well. I would get the crossmember fron the XJ the AX-15 came from if possible. The AX-15 bellhousing will bolt up to your block with no adapters.
Tom
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Unread 03-27-2008, 10:07 AM   #4
Pete M
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crossmembers are all the same. If you do eventually get an AX-15, try to get everything associated with the trans including the trans mount and everything inside and on the bellhousing. Also the 231 if it's still attached. Sometimes it an be had for a cheaper price if bought together. Also, a TJ trans is a bit different and will bolt in, but require a bit of ingenuity (I've got one in my 88 MJ)
--Pete
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-88 MJ; 4.0L, ex-2wd, TJ ax15/231, 78 Ford D44 w/spool, 9" w/posi, 33" trXus MTs, custom roll-bar/bumpers/etc.
Also an 86 MJ Metric ton and 2 '90 MJs
Projects/wheelin' pics: picturetrail.com/petermontie
My email: petermontie@hotmail.com
ComancheClub.com/forums
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Unread 03-27-2008, 10:21 AM   #5
75SV1
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Quote:
Originally Posted by Pete M View Post
crossmembers are all the same. --Pete
That not my experience. I have an '88 with the Peugeout and bought an AX-15 with the cross member out of a 91 or 92. One is flat across and the other has an pocket or a lowered section (the 91 I think). I have both at home. I can double check. I'll search my pictures to see if its in there.
Tom
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Unread 03-27-2008, 10:49 AM   #6
bjmilz
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the previous owner said he replaced the tranny and transfer case, and I plan on getting in touch with him about it. is there an obvious way to see if my tranny is an AX-15 or ba-10/5? And I am assuming the 231 refers to the transfer case?
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Unread 03-27-2008, 11:16 AM   #7
75SV1
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The AX-15 is squarish. There are four parts. The bellhousing, a center section, a plate about 1-1/2 to 2 inches and the section the shifter goes on top of. The BA-10/5 is oval as I remember. The center section of the case is oval and is split on the top and bottom. Look for screw at the bottom holding the two section together. I do have a picture of an AX-15 I could send you. PM me your e-mail if needed. The 231 is the transfer case. I think a used input shaft is about $50. The price list in the article is a bit high. Might try Car-Part.com to see what is available in your area. I don't have pictures of the crossmembers.
Tom
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Unread 03-27-2008, 11:37 AM   #8
bjmilz
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assuming that i have a ba-10/5 and original transfer case, I will need a different bell housing AND transfer case in order to fit an AX-15?
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Unread 03-27-2008, 12:12 PM   #9
75SV1
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Quote:
Originally Posted by bjmilz View Post
assuming that i have a ba-10/5 and original transfer case, I will need a different bell housing AND transfer case in order to fit an AX-15?
You would need a different bellhousing. You could buy the correct input shft for your present transfer case or buy another transfer case. I would try and buy a complete AX-15 transmission, with bellhousing, clutch fork (if external slave), etc. The bellhousing is probably $50-75 in the junk yard.
I look on Car-Part.com for an AX-15 in WI. I used 97 as the year for an external slave. The prices were $200 to $750. The most common price was $400. I don't know what was included in that price. I'd try and get one as complete as possible.
Tom
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Unread 03-27-2008, 01:06 PM   #10
Pete M
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Yes, the NP-231 is the name of the transfercase. The Peugeot has a 21 spline output shaft and the AX-15 has a 23 spline output shaft, so the transfercase needs to match that.
Find out what you have. The AX-15 can be worth rebuilding if you can get a good price for the labor.
The Peugeot has a left and a right half to the main case body. Notice the line of bolts running along the top of the Peugeot. There will be a matching line along the bottom.
Also, if I remember this right, the Peugeot has 3 bolts that hold the shifter column to the case, while the AX-15 has 4.
AX-15 on the left


__________________
-88 MJ; 4.0L, ex-2wd, TJ ax15/231, 78 Ford D44 w/spool, 9" w/posi, 33" trXus MTs, custom roll-bar/bumpers/etc.
Also an 86 MJ Metric ton and 2 '90 MJs
Projects/wheelin' pics: picturetrail.com/petermontie
My email: petermontie@hotmail.com
ComancheClub.com/forums
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Unread 03-27-2008, 01:39 PM   #11
bjmilz
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what is the advantage of having an external slave? btw, thanks for all of the help so far, guys. I am learning a lot very quick!
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Unread 03-27-2008, 04:33 PM   #12
bjmilz
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well here is what I found out from the guy I bought it from.

He replaced the drive shaft, transfer case, and tranny. When doing the swap (trying to install an AX-15 into 88 NP 231), he was not aware of the difference between the 88 and 89-90. He said that the shaft for the tranny had a larger OD(I assume that means 23 spline) than the transfer case, so he had to get a different transfer case.

All and all, I think this means that I have a 23 spline np231 and a bad AX-15.

Now my question is, if I get the 96 or newer AX-15, what else will be required to make this work?

Would you recommend having the current AX-15 rebuilt and put back in, OR get a newer AX-15?
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Unread 03-28-2008, 05:14 AM   #13
75SV1
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Quote:
Originally Posted by bjmilz View Post
what is the advantage of having an external slave? btw, thanks for all of the help so far, guys. I am learning a lot very quick!
The main advantage is that an external slave cylinder can be changed with out pulling the transmission. With an internal, you have to pull the transmission. You'd need to check prices are far as how much it would cost you to rebuild your tranny. I'd guess $800. Versus what one in good shape would cost.
Tom
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