A little help please

[mackdaddytruckfixer]

I have a 88 R model with a 13 speed Fuller RTOL in it. On the air shift side it will not stay in gear more than 10 seconds. The rest of the trans works well I've been running it in 12th but really need OD on the interstate.

[gearhead204]

shut truck off and shift into problem gear then get under the truck and listen for a air leak also check the trans. vent for escaping air. it sounds like to me the control air pressure is being lost and thus the trans falls out of gear in the rear section.

[mackdaddytruckfixer]

no leaks im looking at a reman

[theakerstwo]

A reman would sure fix the problem but its a problem in the rear box that can be repaired by only pulling rear box.

[b61mack]

I had a RTO14613 that did that, the gears for high and low were wore out. when you came up to a stop sigh it would be like in neutral then you would step on the gas it would go back in.

[mrsmackpaul]

I have had very little to do with road rangers as far as working on them if it was a Mack Id say check the air rams for a crook O ring failing that Id say pull the back off might have a whole heap of crap stuck inside the gear where sliding dog slides in the only other thing would be the gears are badly worn either way sounds like the back of the box needs to come off

Paul

[mackdaddytruckfixer]

Thanks for all the reply's I put a reman in for 3k this problem is gone