Transmission Grinds Low to High Range

[TractorHauler]

I've got a transmission that is grinding when the range is shifting from low to high. I got on Eaton's website and got the manuals and it appears that everything in the air system is working properly and it is probably a worn syncronizer gear. The question I have is, how hard is it to remove the auxillary section of the transmission with the tranny still in the truck. Also, is it hard to keep the gears all timed when going back together. Anybody ever done this themselves? Also, any idea what the rebuild of the auxillary section might cost? Thanks for any help!

[moe]

This is surprisingly easy as compared to a trans rebuild. Timing is also easy but you may be able to change syncro assembly with out disrupting. Unless something else is going on or it has a couple million miles you can almost always just replace syncro and that's all it needs. Naturally you will want to inspect for any other damaged or badly worn parts, if it's a 13 or 15 speed you need to look at those syncro's if you do your own work and there's no indication of a problem you can always do that later. PM me if need be and I will give you my number and explain about timing the gears.

[TractorHauler]

How heavy is the aux. section. I am planning on leaving the transmission in the truck and just pulling the aux. section off, but don't know if two people can man handle it or should I have a jack under it. It is a 13 speed transmission but the splitter seems to work great. It seems that just the range grinds. Thanks for the input.

[moe]

I did a 12513 years ago on a cabover with out a jack(with help) but you could stand behind the trans. I would be afraid to attempt it from the ground though. If you do not have a cement pad or floor a piece of plywood and a trans. jack would work fine, or a good size floor jack with another there to help balance it when it comes out. I'm only saying this can be done but I really don't recommend the floor jack version. Sometimes the aux. section is a little stubborn coming out and could surprise you. You could get a couple or longer bolts to put in for security. Going back in can also be tricky, sometimes they fall right in, and sometimes they can have you drinking moonshine before your done. I do highly recommend doing it yourself though. One of the reasons I've been very successful in this business is the money I got to keep by doing jobs like this myself. let me know how it turns out.

[moe]

One more thing, since you've shown interest in doing this job, I've assumed you are somewhat mechanically inclined. If you are not, take it to a shop.

[TractorHauler]

I do consider myself mechanically inclined so I am sure I can figure everything out, but wanted some input before I did the job. One last question. On the Eaton website they mentioned putting some type of lock on the countershaft to hold it from moving while the aux. section is off, will this be self explanitory once I get to it?

[moe]

I'm not sure of what they mean by use a lock but when you pull the countershaft bearings back the countershafts kind of flop and can become untimed and they probably are saying to jam them so they don't come out of mesh with the back gear. You don't have to take the countershafts all the way out to replace syncro assembly, but it is a little tricky. There are keyways on the countershaft and you really need to know how to make sure they are in time before re-assembly. It is one of those things that is very simple once you see it done. You are basically aligning the keyways. One trick is to mark shafts on back and they should be directly in a straigt line from center to center. On inside you mark corresponding teeth to keyway and inside gear on opposite teeth and when you turn shaft they will all mesh. I could explain this much clearer verbally as you could be asking about what I am not making clear because my teaching skills suck. Be careful when installing back half that countershafts are aligned with front section. Do not tighten bolts unless it moves smoothly. I pass through Troy several times a week and will be doing so about 2pm on Sunday. I only have about an hour to play with but if you are doing job close to 61 I wouldn't mind showing you how to time it. I fuel at the Ayerco in Bowling Green 4 times a week.

[TractorHauler]

Moe, I got the aux. section out a couple days ago and have the syncros replaced. They high syncronizer had little to no friction material left on it. I replaced all the parts that looked wore and now have it back together. I will be putting it back in the truck tomorrow. I will let you know how she runs down the road! Thanks for your help, and you were right, it is quite simple once you get in there.

[moe]

Moe, I got the aux. section out a couple days ago and have the syncros replaced. They high syncronizer had little to no friction material left on it. I replaced all the parts that looked wore and now have it back together. I will be putting it back in the truck tomorrow. I will let you know how she runs down the road! Thanks for your help, and you were right, it is quite simple once you get in there.

Good for you! You not only saved money, but also there is a sense of pride felt after completing the job.

[TractorHauler]

Well, all is now done. The transmission shifts great and does not grind any more. Thanks for your help and encouragement Moe!