1987 XJ with downhill problems

Hello all,

Interesting issue, in the process of building up my 87 XJ. New crate engine and AW4 gone through, 4.5" lift trying to build it from the ground up. I live in an area where I go up and down three substantial grades that are going to be covered in snow very soon. Been driving this thing since new drivetrain all summer and never really thought about winter. What is happening is when coming to a grade, like all, I down shift and on all my other vehicles, I can typically do all grades will little touch of the brake. Using tranny and engine for braking. When I shift down, my tranny kicks down and hold me back until I depress the brake. When i touch the brake, the tranny seems to go into neutral and no longer uses gearing to hold you back. 100% braking by pedal. This setup has 1-3 and over drive. Shifting to 1 holds back to much and three does not hold back enough.

I have seen other threads where guys have modified the signal to the AW4 to keep gears locked up for downhill. Has any one done this mod and if so how long have you been running this, and would you recommend? Can't find the thread at the moment but entailed nothing more than splicing three wires going to the TCU and a three way toggle switch.

Help would be appreciated as relying on braking alone in North Idaho....little more fun coming down the hill then normal lol

Good thing to do.

Clearwater Ken said:

Hello all,

Interesting issue, in the process of building up my 87 XJ. New crate engine and AW4 gone through, 4.5" lift trying to build it from the ground up. I live in an area where I go up and down three substantial grades that are going to be covered in snow very soon. Been driving this thing since new drivetrain all summer and never really thought about winter. What is happening is when coming to a grade, like all, I down shift and on all my other vehicles, I can typically do all grades will little touch of the brake. Using tranny and engine for braking. When I shift down, my tranny kicks down and hold me back until I depress the brake. When i touch the brake, the tranny seems to go into neutral and no longer uses gearing to hold you back. 100% braking by pedal. This setup has 1-3 and over drive. Shifting to 1 holds back to much and three does not hold back enough.

I have seen other threads where guys have modified the signal to the AW4 to keep gears locked up for downhill. Has any one done this mod and if so how long have you been running this, and would you recommend? Can't find the thread at the moment but entailed nothing more than splicing three wires going to the TCU and a three way toggle switch.

Help would be appreciated as relying on braking alone in North Idaho....little more fun coming down the hill then normal lol

Click to expand...

http://www.radesignsproducts.com/Rail.html This guy makes a shifter for the AW4 and from what I hear it works very well and he is a great guy to deal with.

Insane, called no kidding four tranny shops within 10 miles of this guy and they all told me was something they had never heard of and would not modify due to liability. Guy is less than an hour away, has some great gear. Thanks for the referral!
Ken

Update:

Went ahead and picked up the RAD shifter. Have to say, this is exactly what I was looking for. Install was easy, not gonna lie after a few calls to Rory. Great guy and great CS. After doing this mod, I would say that total time even with drilling holes is less than two hours and really taking your time. And keep in mind, this was my first electrical mod other than lights and audio so for someone who has wired something similar, 30 mins lol.

In a nutshell, if you have a AW4 and want more control over the gearing, and a fun mid at that, give the RAD rail II a shot.

Clearwater Ken said:

Update:

Went ahead and picked up the RAD shifter. Have to say, this is exactly what I was looking for. Install was easy, not gonna lie after a few calls to Rory. Great guy and great CS. After doing this mod, I would say that total time even with drilling holes is less than two hours and really taking your time. And keep in mind, this was my first electrical mod other than lights and audio so for someone who has wired something similar, 30 mins lol.

In a nutshell, if you have a AW4 and want more control over the gearing, and a fun mid at that, give the RAD rail II a shot.

Click to expand...

Great. Have any pics by chance?

Yes I did snap a few, anything in particular you are looking for?

Maybe of where you mounted it. I dont see online instructions on how to operate it, could ya give us a short explanation?
Do you keep the shifter in drive and only move the rail etc.

I get annoyed when I'm in low gear and it upshifts to 2nd without my blessing.

Kinda don't like the look of the controller but the concept may be what I need.

Yea, I'll do a little write up from start to Finnish if your would like. I did run into a few snags along the way, self made but, got through them.

Regarding the shifter, I have to say, most of the installed pics I saw had the version with the ball on top like a normal shifter. I had seen this version on the website and though to give it a try and if I didn't like it, buddy that is a pro machinist with full shop, 4 Axis and all.

Honestly, after the first time I shifted this, I think I prefer it the way it is. Where mine is mounted, the shifter sits in my hands and is manipulated as it was meant to be there, very comfortable and actually fun to use.

Final installation is what I would like to see.

Ok no worries, I'll snap some shots in the sun tomorrow.

There are some pics showing the installed pieces. Had this in now for just under a week and today I really used the shift function in the mountains on snowy logging roads. I am also wearing a holster with a Sig medium frame and the switch has not interfered yet.

Honestly with the AW4 not holding in gear going downhill was gonna push me to sale this beauty because I drive up and down hills everyday and rotor after rotor is not cool. This is honestly my favorite mod to date. Once you learn the shifting it's cake and a blast.

If my shifter is in drive, I get through the rail 1,34od
When it's in 3rd, I get 1,2,3 4 and when out in the trail using the shifter in 1, I get 1,2 no third and all the way forward on the rail is 1st again.

It's slick to drive using the tranny and as soon as you start to down hill, flip the switch with the rail in 2nd and it's awesome.

Damn auto fill lol

Ok I think I understand lol. Waaaay more options then I need. I'll probably just install a switch to hold first. Thanks for the info.

Thought I would chime back in for a update.

Have the RadII now for over a month. Since installed, the snow has hit and with the onset of a Huge Artic front, driving conditions here in N Idaho have turned interesting. Before this shifter was installed, keep in mind that when going down a hill, and using the shifter for engine braking the moment you touch the brake with a AW4, the tranny free wheels putting most of the braking on the front. Going downhill in ice, or snow, this is a recipe for a insurance claim at best, and here in the mountains going off the road means a short flight and a rapid de-acceleration lol, pain, lots I pain....

This shifter has really made this XJ, my perfect rig. This shifter takes some getting used to but, once you have it it is awesome, and a blast to use. Using the shifter, I am able to traverse nearly any grade without using the brakes. It is great and like I said above, if this did not give me better engine braking, I was going to sale this rig because it would take too much more money to mod this into a good mountain rig.

Huge thanks to Rory, he was awesome to deal with and even after his normal operating hours he was quick to offer a return call if needed. If any one is running into this same issue with their AW4, definitely give this shifter a try and feel free to contact me for help or photos. With new engine, tranny and all the mods I have done, this is no kidding the mod that I would say was my favorite bar none.