2nd gear problem with h42 and toybox (1 Viewer)

[REKCUT]

Posted this in the 60 section with no luck. Thought it might be more in line with this group

Last winter had a toybox put in my 60 with the stock 4spd. I ran it to LSCR without any problems. In June I went to Razorback Ramble and it started acting up. When i use the tranny as a engine brake to go down steep hills, second gear would start to go away. At first it would start jumping out of gear and then it would get to where I could not get it in gear at all. It was like 2nd had moved away from the shifter. I could get back to camp and and take it out on a road and drive it normal and 2nd would slowly come back. The only time it goes away is on steep descents and it comes back with normal forward torque from driving on the road.

When I got home and took off the skid plate, I found that the transmission mount bolt had come loose. I set it again and used it in some easy situations and it seemed fine. Last weekend at FlatNasty w TAC it started acting up again. Not as bad as RR but it was still popping out of gear on hill descents unless I kept my hand on it. I will check the bolt this weekend to see if its come loose again.

There are no other signs of problem. 1st, 3rd, 4th, and reverse are fine and there is no grinding or sliping problems. I dont understand the transmission enought to know what could be causing this. I do know that LSCR had no hills as long as what the other two places had so It may have started at RR or it may just not have been put in a situation that caused it in Texas. It may not be a toybox problem. I just dont know.


Thought, answers,

P.S. I already have someone that has suggested I go back to stock and give the TOYBOX to them, so you dont need to suggest that option

 

[66fj40x2]

Thad, I had an issue with mine popping out of gear on steep inclines. I found the drivetrain was slipping forward just enough for shifter to hit the floor board and slide out of gear. Not sure that would cause you an issue on declines tho.

 

[REKCUT]

I have taken the boot off and its not hitting the floor and its only in second. I dont know of anthing that can move in the tranny that wouldnt cause major damage to the unit like a broken gear. Its odd and I hate to drop the whole thing without some kind of direction to go.

PS mike, thanks again for the axle help.

 

[Mace]

Sounds to me like your tranny is going south.

 

[REKCUT]

its not like that. It only happens on steep decents and stays that way until you reverse the torque by applying highway speeds.

 

[Tapage]

diying sincro .. ?

 

[REKCUT]

diying sincro .. ?

Dont know. It never grinds going in. It just moves away and comes back with reverse torque. If the syncro was bad you should be able to turn off the truck and get it in gear. I also dont see how that would come and go with the same reasons I described. It also wont do it without the toybox engauged. I can down shift all I want in high or 4 low, but it start happening with the box engauged.

I also got a suggeston of a detent spring. Not sure how that works or if it applies.

 

[Mace]

its resistance downstream of the tranny that is making the problems come forward.

Synchro is going bad.

Been that way in my 40's 420 for a while. Unfortunately SM420 synchros are hard to find now a days..

 

[NocalFJ60]

Have you called and talked to Marlin? I don't know enough about transmissions to tell you anything.

Goodluck

 

[REKCUT]

I couldnt get marlin to help me with anything on the install. On my last try to get help from them on the install I was told that I was putting a product(toybox) in somthing that it wasnt designed to fit in and that I needed to work it out on my own.

 

[REKCUT]

its resistance downstream of the tranny that is making the problems come forward.

Synchro is going bad.

Been that way in my 40's 420 for a while. Unfortunately SM420 synchros are hard to find now a days..

Finally Mace. I was extremely dissapointed that you would give the generic advice of "your tranny is going south". I expected that, and got it, from folks with 100 post.

When you talk about resistance, why would it only happen when the toybox is engauged. My lack of help from Marlin makes me wonder if something was installed wrong. not to change the subject but I also cant shift from 2 - 4 on the fly since the install. Wonder if thats related.

 

[NocalFJ60]

I couldnt get marlin to help me with anything on the install. On my last try to get help from them on the install I was told that I was putting a product(toybox) in somthing that it wasnt designed to fit in and that I needed to work it out on my own.

Call and ask to talk to Marlin. The 4 speed is listed on their webpage to bolt-up to the toybox. Marlin is very helpful but I have just talked to him in person. He might be hard to reach on the phone.

 

[Mace]

I couldnt get marlin to help me with anything on the install. On my last try to get help from them on the install I was told that I was putting a product(toybox) in somthing that it wasnt designed to fit in and that I needed to work it out on my own.

huh??

There is an adapter to bolt the toybox to the 4 speed. Sounds like something is designed there...

As far as popping out of gear....

As I understand it, what happens is that the pressure from the angle cut in the gears is reversed when compression braking. Instead of keeping the gears together by the motor providing power, you are basicaly "forcing" the tranny out of gear byt he tires "providing" power and the motor providing resistance. It is not the toybox that is causing it, but it will amplify it considering how much more "reverse" torque you are putting on the motor..

 

[REKCUT]

Now you are on a line of thinking that makes some kind of sence to me. I understand what your saying but my knowledge of how transmissions works is limited. I dont understand why it would only effect 2nd gear?

 

[Mace]

Now you are on a line of thinking that makes some kind of sence to me. I understand what your saying but my knowledge of how transmissions works is limited. I dont understand why it would only effect 2nd gear?

pure wear, what gear do you hit every time you go around a corner?
1st you generally come to a stop before you stick it in.

 

[zuluzeugma]

you generally come to a stop before you stick it in.

Thats what she said...




I have a stock FJ60 4-speed i'll practically give you if you want it...