Engaging 4hi low questions

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Eric78chief
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Engaging 4hi low questions

Post by Eric78chief »

New to the board. Have a 78 Cherokee chief wide-track with the part time conversion Quadra Tran installed. I’m having issues with sequence of using 4x.

Basically I turn it on in park flip the e-drive to on. It works. I then try to go into low and it grinds gears and I have to turn the truck off to stop everything and put it into either low or drive. Stupid question but should I be able to put the car in low while moving or do I go into park to switch.

Thanks for the help!
Eric
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Cecil14
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Re: Engaging 4hi low questions

Post by Cecil14 »

Low is never (to my knowledge) synchronized. In every 4wd vehicle I've ever driven, you have to come to an almost complete, if not totally complete, stop to engage low range. I don't know if park is required in the Q/T rigs or not, but a dead stop likely is at very least.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

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Eric78chief
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Re: Engaging 4hi low questions

Post by Eric78chief »

Thanks for the reply, if I stop do I leave it in drive or pop the transmission into neutral then switch? And when I try to go back to hi it leaves me between gears and grinds anyway I try to move the transfer case lever.

Sorry I’ve worked hard going through every system and I’m now working the 4x and trouble shooting/ not trying to break something on accident.
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Cecil14
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Re: Engaging 4hi low questions

Post by Cecil14 »

I haven't owned a Q/T rig, so I can't comment on the specifics. Check out the manuals here:

http://oljeep.com/edge_parts_man.html

There's a 1977 owners manual (should be the same as 1978 for this purpose), that should give you the official shifting procedure. There's also a 1978 TSM, which will give you all the technical details.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

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Eric78chief
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Re: Engaging 4hi low questions

Post by Eric78chief »

Thank you!

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Eric78chief
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Re: Engaging 4hi low questions

Post by Eric78chief »

Ok found it. Slip into neutral coasting while you move into 4lo. Last question. I have locking hubs on the front and the mile market part time conversion. Am I I. 4weel high as soon as I lock the Huns or do I need to flip the glove compartment switch to emergency drive as well?
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Cecil14
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Re: Engaging 4hi low questions

Post by Cecil14 »

You will definitely need to have the hubs locked, but I believe you will be in 2wd until you hit the e-drive switch. I would prefer someone more familiar with the Q/Ts jump in with confirmation, though. It's easy enough to check: with the hubs unlocked and the e-drive switch off, try to spin the front driveshaft by hand. Now try it with the hubs still unlocked, but e-drive on. That should tell you which is which.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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tgreese
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Re: Engaging 4hi low questions

Post by tgreese »

This is what I recall...

With a part-time kit, your e-drive switch now controls the change from 2WD to 4WD and back. The hubs must be locked to go into 4WD. Unlike a conventional transfer case the part-time Quadratrac does not support shift-on-the-fly between 2WD and 4WD. Come to a full stop in park, hubs locked, and shift. Same procedure as your owner's manual describes for shifting into or out of e-drive, with the addition of the hubs.

To the interested, the part-time Quadratrac shifts just like a Dana 20, except it does not have gears that mesh to give you shift-on-the fly between 2WD and 4WD. Instead it has a lock pin that enables e-drive, and it's not designed to engage while moving.

The low range is a separate planetary transmission on the back of the transfer case, and it does not care if you are in 2WD or 4WD. You cannot change range while moving under power. AFAIK no 4WD system exists that allows shifting range while moving - don't try. If the owners manual suggests any movement, they mean moving at the barest baby crawl, just enough to help the gears to mesh. No power, barely moving - try it standing still first. Again, follow the instructions in the owner's manual.

Don't want to sound too authoritative here ... this is what I recall from my days with these cars, 40ish years ago. The main thing is the part-time kit kludges up the Quadratrac so it sort-of works like a part-time case. There are differences, and you have to think about what you are doing when you operate it. Any gear grinding is wrong ... at most I would expect a muted clunk when it moves into gear.
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fulsizjeep
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Re: Engaging 4hi low questions

Post by fulsizjeep »

I bet there is some wear inside the low range. Remember, all the power to move the Jeep goes through the low range unit first. Switching from Lo to Hi or Hi to Lo works best if you are barely moving regardless of stock or part time configuration. I put a NOS low range on my wife's Waggy a few years ago. It shifts better than any I have tried but still have to kill the engine once in a while to finish the shift. Before I put in the NOS lo range, we always had to shut off engine to complete the shift with the two previously used low range units.

"To the interested, the part-time Quadratrac shifts just like a Dana 20, except it does not have gears that mesh to give you shift-on-the fly between 2WD and 4WD. Instead it has a lock pin that enables e-drive, and it's not designed to engage while moving." I am not aware of this lock pin. You can throw the vacuum switch any time but that is not recommended. Sometimes you need to roll just a little for the Edrive/2wd-4wd shift to complete and have the indicator light go on or off. The shift fork has nylon pads on it. If these are worn or broken, that can play hell on shifting.

QT info also found here:
http://jubileejeeps.org/quadratrac
Flint Boardman
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https://jubileejeeps.org/quadratrac

will e
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Re: Engaging 4hi low questions

Post by will e »

I never owned an original Quadra Trac but I have had transfer cases that work best if the jeep is moving slowly and in neutral. I generally try shifting in/out while on a hill. I stop the truck, put it in neutral, take my foot off the brake and as I start to roll forward I shift the transfer case.

I do this because sometimes it wouldn't shift or would stop in neutral. Being on the hill allows me to stop the Jeep and try again.

If you find yourself 'not moving' and in Neutral in both the transfer case and transmission and the TC won't shift do NOT put the transmission into park. You will get that nasty grinding sound. In these situations I will turn the engine off, then put the transmission in Park and try the shift again.
81 Waggy 'WILL E' Retired
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letank
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Re: Engaging 4hi low questions

Post by letank »

for the QT converted or not, NO shift on the fly, preferably on level ground (1), engine in neutral for maximum manifold vacuum to give the maximum boost to the vacuum activated shifter.
When my Low range cable started to rust a bit, I would stop on flat ground, put in neutral and crawl with an open end wrench to activate the lever... wheel choke are recommended...

If you have part time conversion you can use the low range in 2WD

(1) on the first Ouray trip I was unable to shift to low range on an uphill, and had to roll back to level ground.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

Cheap Hobby
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Re: Engaging 4hi low questions

Post by Cheap Hobby »

With the part time kit installed the vacuum control works opposite of stock, there may be a sticker over the original factory sign. I will try to find the sticker and what is left of my glove box tonight and get a picture up.
For the low range that is a separate gear driven unit attached to the case. The easiest and less damage way is to put trans in park with every thing stopped and shift to low range. You will want your foot on the brake, hard like you don't want to go off a cliff hard, you will be putting the transfer case in to neutral as you shift. You can also do trans in neutral but any motion in trans will cause grinding and binding.
79 Cherokee WT QT Golden Eagle white with gold windows "Pigger" only blows hubs the night before a road trip or the clodest night of year. Has only been towed cause of stupid.
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