Mod for the Gearbox?

[Santeh]

Hello all,

I read a while back that there was a mod for full-sized Jeeps that tightens up the gearbox allowing the station wagon to drive more like a modern car via a tighter feel to the steering column. As I am doing a lot of work with my 1978 Cherokee I went looking for the information on the mod but I have not been able to find it. Does anyone happen to know about this type of modification? If someone has done the mod, what did you think of it?

Thanks all!

[tgreese]

I think you are referring to the instructions for tightening the gear mesh on the steering gear. This is contrary to what the TSM instructs, so if that how-to is gone it's a good thing IMO. Just read the TSM and it tells you how to adjust the steering gear. The right way is first adjust end play before adjusting gear mesh. It should be done on the bench, and you'll need an inch-pound beam-type torque wrench.

In a live axle front end, there are plenty of places for parts to wear and get loose. This has been discussed many times on the forum - search here and at IFSJA and you'll find plenty of threads to read. Also, if the Jeep has been lifted, the caster is likely too low and that makes the Jeep track poorly. So, worn loose parts and alignment.

The "feel" of the factory steering is very light. You can easily palm the wheel to parallel part. Some have replaced the steering gear with a newer gear from a 4WD S10 or Blazer. This gear is both more durable and has a variable ratio so that it turns more quickly as you steer away from center. This topic has also been discussed extensively in old threads.

[SJTD]

The way to adjust the feel involves replacing the little shaft you see sticking out of the end of the input shaft to a thicker one. Total disassembly required. It determines when/how much fluid is applied to the piston in the box.

Adjusting gear mesh is to eliminate play not adjust feel. If that thread was about improving feel I agree with tg; it is better left burried.

I've wondered aboot using a longer arm. It would give more feel and quicker steering. Too quick???

[Santeh]

I think you are referring to the instructions for tightening the gear mesh on the steering gear. This is contrary to what the TSM instructs, so if that how-to is gone it's a good thing IMO. Just read the TSM and it tells you how to adjust the steering gear. The right way is first adjust end play before adjusting gear mesh. It should be done on the bench, and you'll need an inch-pound beam-type torque wrench.

In a live axle front end, there are plenty of places for parts to wear and get loose. This has been discussed many times on the forum - search here and at IFSJA and you'll find plenty of threads to read. Also, if the Jeep has been lifted, the caster is likely too low and that makes the Jeep track poorly. So, worn loose parts and alignment.

The "feel" of the factory steering is very light. You can easily palm the wheel to parallel part. Some have replaced the steering gear with a newer gear from a 4WD S10 or Blazer. This gear is both more durable and has a variable ratio so that it turns more quickly as you steer away from center. This topic has also been discussed extensively in old threads.

Hello!

Actually this is excellent news as it is, in essence, one less mod to invest into which is a relief. I will simply have my mechanics take a close look at the gear box, etc., to look for wear (thankfully I already redid the front end which certainly helped).

Thanks again!

[Santeh]

The way to adjust the feel involves replacing the little shaft you see sticking out of the end of the input shaft to a thicker one. Total disassembly required. It determines when/how much fluid is applied to the piston in the box.

Adjusting gear mesh is to eliminate play not adjust feel. If that thread was about improving feel I agree with tg; it is better left burried.

I've wondered aboot using a longer arm. It would give more feel and quicker steering. Too quick???

I may have indeed mispoke as I was thinking of play (which I interpreted as feel), thus I apologize for that. I just noted when driving that I have to do a lot of small corrections with the steering wheel to keep the verhicle where I want on the road, which is exasperated by driving at higher speeds such as on the freeway. I find this a little unnerving as it seems as if I make a small inocrrect adjustment it might have very bad consequences. I know the wagon is 40 years old thus I do not expect it to drive like a modern vehicle, but any way to lesson the play would be nice!

[tgreese]

What exactly is new in the front end? Did you replace the springs? Tie rods?

Have your local tire shop do an alignment. Ask for the printout from the alignment machine. Post it up here for us to look at.

The shop will only be able to adjust the toe-in and center the steering easily/cheaply, but you want the printout from the machine.

Steering on these cars is light, and road feel in the steering wheel is minimal, but they should not be scary or tedious to drive.

[SJTD]

Yeah, need to know what the caster is. Even with all new parts, not enough caster coupled with play in the box will make freeway travel exiting.

You should be able to find instructions for adjusting the steering box on the web. Pretty sure the factory manual covers it. As tg said above, need to do it on the bench in the right order and you need a torque wrench.

[Santeh]

Thanks all! I appreciate the thoughts and help!

I redid the tie rods and sleeves, and have had an alignment, but I am not sure about the casters. Unfortunately a picture will have to wait as the Jeep is in the shop and might be there awhile as it has rear seal and transmission leaks. Sadly with the rear seal leak I am told that the engine will need to be removed to fix it, thus since the engine might be coming out there is now a discussion about rebuilding the 360 V8 so as to save money down the road. It is too bad I do not have more money as I have a free year 2000 LS1 I could put it, but I can barely afford the 360 rebuild and the LS1 swap has been priced by several places in my area as up to twice the cost as a rebuild.

However, it is because the wagon might be down for a while I thought I would investigate the gearbox issue. I am sorry that I cannot get a picture for a bit.

[1979bettywhite]

Are you referring to the rear main seal? The engine does not need to be removed to replace the rear main seal. You may want to investigate using another shop that has some experience with the AMC 360. Mine was done by a reputable shop and got it back within the day. They replaced the pan gasket at the same time as well. This is a pretty routine job. A crappy one, but still pretty routine. And as an FYI, you may never get a completely dry rear main seal. It may still leak a little bit, but should not be too bad.

Assume the tranny leak may be coming from the pan there as well (at least that's where I would start looking). Not a bad job to change that gasket as well on the TH400. Cheap and easy way to eliminate one potential leaky area.

I would once again have a reputable shop do a diagnostic check on the engine before I succumbed to a complete rebuild. Compression/leak down/bearing wear etc. Even with some wear on these things they can run for a long time as long as you keep up with routine maintenance and change the oil out at a decent frequency. I have low oil pressure at idle and probably 95k+ on mine. But still running quiet and smooth. A rebuild is in my future, but still getting current enjoyment out of her.

[Santeh]

Are you referring to the rear main seal? The engine does not need to be removed to replace the rear main seal. You may want to investigate using another shop that has some experience with the AMC 360. Mine was done by a reputable shop and got it back within the day. They replaced the pan gasket at the same time as well. This is a pretty routine job. A crappy one, but still pretty routine. And as an FYI, you may never get a completely dry rear main seal. It may still leak a little bit, but should not be too bad.

Assume the tranny leak may be coming from the pan there as well (at least that's where I would start looking). Not a bad job to change that gasket as well on the TH400. Cheap and easy way to eliminate one potential leaky area.

I would once again have a reputable shop do a diagnostic check on the engine before I succumbed to a complete rebuild. Compression/leak down/bearing wear etc. Even with some wear on these things they can run for a long time as long as you keep up with routine maintenance and change the oil out at a decent frequency. I have low oil pressure at idle and probably 95k+ on mine. But still running quiet and smooth. A rebuild is in my future, but still getting current enjoyment out of her.

This may not sound the best yet I do not mean it as such, thus please forgive me. However I already spoke to three shops in my area (who specialize in older cars) and all said the same about having to remove the engine in my 1978 Cherokee to fix the rear main seal. I certainly would prefer not to do so as my engine seems to be okay overall, but I wonder why shops in my area seem to want the full rebuild if it is not required (save for maybe wanting more money out of me ). Thankfully the transmission fix did indeed seem straight forward and fairly inexpensive (around $500).

[Santeh]

Are you referring to the rear main seal? The engine does not need to be removed to replace the rear main seal. You may want to investigate using another shop that has some experience with the AMC 360. Mine was done by a reputable shop and got it back within the day. They replaced the pan gasket at the same time as well. This is a pretty routine job. A crappy one, but still pretty routine. And as an FYI, you may never get a completely dry rear main seal. It may still leak a little bit, but should not be too bad.

Assume the tranny leak may be coming from the pan there as well (at least that's where I would start looking). Not a bad job to change that gasket as well on the TH400. Cheap and easy way to eliminate one potential leaky area.

I would once again have a reputable shop do a diagnostic check on the engine before I succumbed to a complete rebuild. Compression/leak down/bearing wear etc. Even with some wear on these things they can run for a long time as long as you keep up with routine maintenance and change the oil out at a decent frequency. I have low oil pressure at idle and probably 95k+ on mine. But still running quiet and smooth. A rebuild is in my future, but still getting current enjoyment out of her.

This may not sound the best yet I do not mean it as such, thus please forgive me. However I already spoke to three shops in my area who specialize in older cars and all said the same about having to remove the engine in my 1978 Cherokee to fix the rear main seal. I certainly would prefer not to do so as my engine seems to be okay overall save for the carburetor (the reason I added a FiTech), but I wonder why shops in my area seem to want the full rebuild if it is not required save for maybe wanting more money out of me. Thankfully the transmission fix does indeed seem straight forward and fairly inexpensive (around $500).

[1979bettywhite]

Oh, I do understand you are not trying to sound negative etc. These are probably decent shops. They may just not want you to go through a minor repair when the inevitable rebuild is looming. Trying to save you some $ to do everything at once instead of having to do the RMS twice if you do choose to rebuild. So once again, I would want to know the overall health of my engine before choosing to rebuild it. Kind of like getting open heart surgery done without first getting an EKG, lol.

Here is a good write-up on the mothership for the RMS:

http://www.ifsja.org/tech/motors/rearmainseal.html

This is derived almost word for word from my 1977 TSM, just checked:

http://oljeep.com/gw/77_tsm/04%201977%2 ... Engine.pdf

Page 1B-26. You could even print that and take it to the shop.

[Tatsadasayago]

The steering issue sounds like there is not enough positive caster.
As far the the rear main seal goes, YES, it can be changed without removing the engine. Drop the pan, loosen the main cap bolts, drop the rear cap and install the new seal after a good cleanup. These guys you spoke with are either ignorant or trying to gouge you. I wager it's ignorance that leads them to believe it's a one-piece seal...

[Cheap Hobby]

When you do the rms make sure you do not get the new and improved red rubber felpro offers. It dose not fit. Get the old black one.

[Fire1]

Hi there Cheap Hobby, I was just about to order a rear main seal and saw your post. Do you recommend any particular manufacturer? I saw Morris 4x4 sell Crown and JC Whitney sell Felpro and Crown. Any advice on the preferred seal manufacturer would be appreciated. Thanks.

[Cheap Hobby]

Sorry Fire1 ive been tied up with major sinus infection and taxes yeha. I always use felpro rms as they are oem. Get the black seal not the new and inproved red one. The red one is for Chrysler 360 not Jeep 360 and is not the correct length.