Maxitorqe 13Spd

[spazzn1]

I'm looking at an 1998 RD688 Dump that has an E7 350 engine with a Maxitorqe 13 speed transmission. The truck only has about 320,000 miles on it. The seller states that they can't get the transmission to go from the low side to the high side. It shifts thru all the gears on the low side fine, just can't get it to go on the high side. Never been around Mack transmissions, and just wanted to see if there might be any suggestions on whether there might be an easy fix to this. I was hoping it might be a simple air problem with it. I would really appreciate any suggestions you guys might have.

Joey

[HK Trucking]

I'm looking at an 1998 RD688 Dump that has an E7 350 engine with a Maxitorqe 13 speed transmission. The truck only has about 320,000 miles on it. The seller states that they can't get the transmission to go from the low side to the high side. It shifts thru all the gears on the low side fine, just can't get it to go on the high side. Never been around Mack transmissions, and just wanted to see if there might be any suggestions on whether there might be an easy fix to this. I was hoping it might be a simple air problem with it. I would really appreciate any suggestions you guys might have

Joey

The range shift synchro has taken a dump and the teeth are stripped off the high side from excessive grinding.

That's epidemic on the Mack T2090, T2130, and T2180 transmissions.

You can replace the range shift setup without removing the entire trans, just pull off the back section.

Don't tell the seller that, just tell him the trans is junk, and negotiate the price accordingly.

.

[theakerstwo]

HK have you ever did that with out the plates to hold the shafts up? I did on a cab over one time and glade when i was done with it. I am look at doing it to my 9 speed soon. glenn

[Gambi80]

My 18sp grinds on the range shift on the first shift of the day in the a.m. though not every time. I suppose that's the beginning of the end...?

[theakerstwo]

My 18sp grinds on the range shift on the first shift of the day in the a.m. though not every time. I suppose that's the beginning of the end...?

Your right

[Gambi80]

Sonofabitch!

[HK Trucking]

My 18sp grinds on the range shift on the first shift of the day in the a.m. though not every time. I suppose that's the beginning of the end...?

You can postpone it's demise by making the first few range shifts of the day between 3rd lo and "lo" hi range instead of from 4th to 5th as you normally would. This allows the shift to happen at a lower speed and there is less strain on the range shift synchro that way. Then once it's warmed up, you can resume shifting it the normal way.

The key is to prevent that severe grinding and jamming that eventually will wear the teeth down to the point that it jumps out of hi range when you put the power to it.

Glenn, no I did not have plates.

[theakerstwo]

You can postpone it's demise by making the first few range shifts of the day between 3rd lo and "lo" hi range instead of from 4th to 5th as you normally would. This allows the shift to happen at a lower speed and there is less strain on the range shift synchro that way. Then once it's warmed up, you can resume shifting it the normal way.

The key is to prevent that severe grinding and jamming that eventually will wear the teeth down to the point that it jumps out of hi range when you put the power to it.

Glenn, no I did not have plates.

I need to start trying to get me some plates because my trans will drag one time in the moring and i think it helps to shut it down at night in hi range and the shift like you said.I wish i had a 12 speed in it because the o/d is too big for a dump truck.

[spazzn1]

I need to start trying to get me some plates because my trans will drag one time in the moring and i think it helps to shut it down at night in hi range and the shift like you said.I wish i had a 12 speed in it because the o/d is too big for a dump truck.

Thanks for all of the input, doesn't sound like an easy fix liked I had hoped. The truck is over 5 hours away, in which case it will have to hauled, which will take away any money saved on the truck. Thanks again.

Joey

[BulldogVision]

The 9 speed in my 95 ch did the same thing.The syncros eventually went out. I put a reman trans in it and ran it for 8 years with no problems, and that was local work. lotsa lites and stops. My shop told me it really helps to wait until you are going as slow as possible before downshifting into the low box, such as rolling up to a stop sign or lite........

[bullhusk]

Gambi80 thats how my T 2090 started sorry BULLHUSK

[ozrad7]

I just had the same problem with the 10 speed in my r model,turns out the circlip in the bottom of the spitter cylinder had broken and the loose piece nicked the large o ring on the piston.cost me $15 to repair and only had to remove the cylinder which near on sticks out the rear of the cab on a r model.now shifts perfect.