Threaded Mode | Linear Mode

Mr Hagg · 05-09-2017, **(Subject: Hard shift high to low range )**

If the truck was to be in our shop i would first listen to it going into high and low. You can tell it the air pressure is not good as it will drag somewhat.
If it does drag I would remove the 4 bolts in the rear of the upper back bock where the piston it for the shift range (upper one) you can buy a kit that has the piston oring and other orings and gaskets needed. I find many times the barrel where the piston slides will be rusty from moisture in the system. I take cleaner and some fine sand paper and clean it up..INstall the new o'rings and you are good to go..

If it sounds like its got good air pressure and is working good but only slams when going down the road Id pull the back back and look at syncro. Many times when these go back it will slam ALL the time not just every now and then... It will also have a grinding sound of noise to it when it does it.. Many times the failure of this is because drivers flip the range on the shift to soon before they come to a stop. You will know its not right cause you will hear the transmission speed up and make a wining sound.

So with out checking into it further it really is hard to be able to tell you for sure..

flonly · 05-09-2017, **(Subject: Hard shift high to low range )**

Mr hagg I am glad you responded to this cause i have same symptom with mine and will be seeing you Monday for inframe so mabey a little transmission work also

Mr Hagg · 05-09-2017, **(Subject: Hard shift high to low range )**

Ok sounds good... Transmission are pretty simple just a few gears and air shift...

Mrkentee · 05-09-2017, **(Subject: Hard shift high to low range )**

(05-09-2017 )Mr Hagg Wrote: If the truck was to be in our shop i would first listen to it going into high and low. You can tell it the air pressure is not good as it will drag somewhat.
If it does drag I would remove the 4 bolts in the rear of the upper back bock where the piston it for the shift range (upper one) you can buy a kit that has the piston oring and other orings and gaskets needed. I find many times the barrel where the piston slides will be rusty from moisture in the system. I take cleaner and some fine sand paper and clean it up..INstall the new o'rings and you are good to go..

If it sounds like its got good air pressure and is working good but only slams when going down the road Id pull the back back and look at syncro. Many times when these go back it will slam ALL the time not just every now and then... It will also have a grinding sound of noise to it when it does it.. Many times the failure of this is because drivers flip the range on the shift to soon before they come to a stop. You will know its not right cause you will hear the transmission speed up and make a wining sound.

So with out checking into it further it really is hard to be able to tell you for sure..

I know the grinding you're talking about. My last truck had that soon after I bought it. This doesn't have that at all.
So it's the upper valve that controls hi/low range. That sounds like something I should do. I know I need a compressor and air drier, as there is oil on the bottom of the drier, and the truck has 750,000 miles on it.
Thanks for your input.

Mr Hagg · 05-10-2017, **(Subject: Hard shift high to low range )**

Ok sound like its just a air issue then. It is easy to do. Remove the 4 bolts and knock off back cover you will see the piston and it will have a big nut in the center. At this point you should be able to know it something is wrong..If you are in ga bring it by and i can walk you through how to do it.. Im sure some of the other guys here could too...

Mrkentee · 05-10-2017, **(Subject: Hard shift high to low range )**

(05-10-2017 )Mr Hagg Wrote: Ok sound like its just a air issue then. It is easy to do. Remove the 4 bolts and knock off back cover you will see the piston and it will have a big nut in the center. At this point you should be able to know it something is wrong..If you are in ga bring it by and i can walk you through how to do it.. Im sure some of the other guys here could too...

I got the kit. If I was in Georgia, I would stop by.
I was thinking about doing it tomorrow afternoon if I got some free time. But maybe this should wait until I'm in my driveway, so I'm not pushed for time, etc.
I hope it's obvious when I look in there.

Mrkentee · 05-15-2017, **(Subject: Hard shift high to low range )**

new doc 2017-05-15 18.33.18_20170515183406809.pdf (Size: 139.77 KB / Downloads: 213)

I got my transmission sample back. Everything is ok except copper, which is double what it should be, according to the lab. What should I look for?

Mr Hagg · 05-15-2017, **(Subject: Hard shift high to low range )**

Copper????? What is your transmission number? Only thing I can think is copper would be cooler? If its a FRO????? and has the one cooler on inside I think I might be looking at changing it out...

Mrkentee · 05-15-2017, **(Subject: Hard shift high to low range )**

(05-15-2017 )Mr Hagg Wrote: Copper????? What is your transmission number? Only thing I can think is copper would be cooler? If its a FRO????? and has the one cooler on inside I think I might be looking at changing it out...

It was RTOCM-16909A (9 speed) but is now
RTLO-16913A (13 speed). Converted to 13 speed.
It has an external liquid cooler on top of it.
It also has a PTO on it.