Worn bushings and banging into reverse related?

[Dave _S]

Hi all,

I replaced my front axle shaft U-joints this weekend in attempt to reduced driveline slop. After doing this I had a friend move the steering wheel back and forth and noticed that the leaf springs, shackles, and sway bar moved side to side with the wheel movement. Even the frame rails moved a little. Apparently, the 23 year old bushings are completely shot. Now I know why the steering is a little sloppy. However, does anyone think this could cause the banging into gear when shifting into reverse problem. Possibly front axle windup or something.

The driveline slop problem has been discussed a lot recently, however, I've never heard or come up with a rationale as to why teh driveline bangs only in reverse and does not bang in drive. Any ideas?

Dave



------------------
1977 WT Cherokee, 401V8, TH400 Quadra-trac. Girlfriend calls it the Whale. I complain about both, but can't seem to get rid of either.

[GM Killer]

The reverse "bang" is most likely from the 10 spline output shaft of the tranny wearing down its partner inside the t-case.

------------------
Matt~
79 Cherokee Cheif Wide Trac
Transplanted 401 w/ Edelbrock Performer Package
TH400 / Q-Trac
4" Skyjacker Softride lift
3 inch bodylift
35" Mud T/A's
____________________
99' Mustang Cobra -
320 HP F-body eater
____________________
93 Mustang Coupe 4 Cyl
Soon to have a transplanted 351w homemade twin turbo set-up :)

[Dave _S]

If the splines were worn, wouldn't the tans bang going from revese to drive? What it does is bang going into reverse from nuetral or drive. Going the other way there is no bang. Seems like if the splines were worn it should bang going from reverse to drive as well, but it doesn't.

Anyway, how would one check to see if the splines were worn? Sounds like you would have to remove the T-case and the trans output shaft to check the fit of the parts.

[Dave _S]

I called Harvey's Complete Jeep Shop in Long Beach and discussed the reverse bang problem with the owner. He says that a worn trans input shaft can cause the problem, though he didn't really have an explanation as to why it doesn't bang in the opposite direction.

Interestingly, he also said a worn QT low range unit can cause the problem.

In his experience, these are the primary causes of this problem. Needless to say the cost of replacing a worn trans output shaft probably exeeds the value of the old Chero.

The guy wants $76 dollars to diagnose the cause. I think I will take mine in and have the guy check it out.

Anyone know of a junkyard in So. Cal. that has some TH400-QT's available cheap?

[BIGUGLY]

This is a problem common to QT cases and caused by the 10 spline output shaft. I have had 3 and they have all done the same thing. At some point you will spin the output shaft, however so far(knock on wood)none of mine have done it in 300,000Est.miles. Don't fix it utill it breaks? Welcome to the esoteric world of FSJ.

------------------
79 Cherokee
BIGUGLY
360 Stroker/TH400/QT/44's
edelbrock performer pac
3"lift 33x12.5

[Dave]

The output shaft drives the sungear in the low range unit or the drive coupler in QT without low ranges. The 10 spline shaft wears on itself and the sungear causing a loud band going into reverse. Last time I checked the output shaft (pn j8122705) was about $175 and the sun gear (pn j81227708) was discontinued. I just live with it!

------------------
Dave
79 Wagoneer
"BOHICA"

[ClarkGriswald]

I would guess that the reason it bangs in reverse and not forward (my 88 g.wag does the same thing) is cause it runs in forward about 99 percent of the time and only in reverse now and then.. so like anything, the wear pattern is biased one way (forward in this case) makine the opposite operation akward and no doubt probably more prone to wear.. just like if you chopp a log with an axe from only one direction.. when you finally get a chunk out of the other side.. its gonna be a big one

------------------
88 Grand Wagoneer
D44's front\rear
AMC 360
TF 727
NP 229 (Funky)
Bone Stock (for now)
NO RUNNING BOARDS!

[Dave _S]

"The output shaft drives the sungear in the low range unit or the drive coupler in QT without low ranges. The 10 spline shaft wears on itself and the sungear causing a loud band going into reverse. Last time I checked the output shaft (pn j8122705) was about $175 and the sun gear (pn j81227708) was discontinued. I just live with it!"

Guess, I'll just have to live with it for now.
Seems like there's got to be someway around this. Maybe find a TH400/Dana 20. I believe those TH400's had 20 spline output shafts.

Someone once told me that all 401 cranks were drilled for pilot holes. Very long term project (if ever) but maybe a 4 speed manual/Dana 20. Then, again the late model Dana/Spicer 18's used the same 1 1/4 inch output shaft as the Dana 20 so perhaps that's an option.

Anyway, thanks for the info.
Dave

[Dave Slingluff]

I have the same problem with my suspension bushings down here is San Diego. Here is a good source for bushings (the only one I could find for my '69). Let me know if you find other sources and how you remove and install.
http://www.espo.com/

[Dave _S]

The '77 TSM describes a threaded rod and washer arrangement for pushing out and pressing in the bushings. You can probably get the threaded rod from Home Depot. I will photocopy the relevant pages from the TSM and mail them to you if you want them. Just send me an address.


<BLOCKQUOTE>quote:</font><HR>Originally posted by Dave Slingluff:
I have the same problem with my suspension bushings down here is San Diego. Here is a good source for bushings (the only one I could find for my '69). Let me know if you find other sources and how you remove and install.
http://www.espo.com/

<HR></BLOCKQUOTE>

[scotty]

pretty much the only thing that you can put on a quadra trac 400 is another quadra trac. theyve got that long,goofy outputshaft that goes way into the t case. to swap in a dana 20 youll need to swap the whole tranny,or swap the output shaft and adapter onto your tranny. if i had a QT,id start looking for a gm th400 with a 205 attached to it. you can swap in the gm tailshaft and adapter and mount the 205 onto the amc 400.now youve got a gear driven case,and you can make a twin stick for the 205 that even gives you a front wheel drive high range. it dont get much stronger than a that...

[GM Killer]

<BLOCKQUOTE>quote:</font><HR>Originally posted by BIGUGLY:
This is a problem common to QT cases and caused by the 10 spline output shaft. I have had 3 and they have all done the same thing. At some point you will spin the output shaft, however so far(knock on wood)none of mine have done it in 300,000Est.miles. Don't fix it utill it breaks? Welcome to the esoteric world of FSJ.

<HR></BLOCKQUOTE>

So what usually breaks? The output shaft or the sun gear?



------------------
Matt~
79 Cherokee Cheif Wide Trac
Transplanted 401 w/ Edelbrock Performer Package
TH400 / Q-Trac
4" Skyjacker Softride lift
3 inch bodylift
35" Mud T/A's
____________________
99' Mustang Cobra -
320 HP F-body eater
____________________
93 Mustang Coupe 4 Cyl
Soon to have a transplanted 351w homemade twin turbo set-up :)