2120 lazy shuttle

[harrydodge]

just bought a 1991 2120 with shuttle shift sometimes it shifts hard .changed trans /hyd oil and filter man where they dirty.put new filter on and added new oil still shifts hard like hyd clutch is not working right .I was wondering if there is a way to flush out the system .add diesel or is there a trans flush i could buy . the clutchs don't slip i have used it to move dirt and it will spin the tires in 4 wheel drive .any thoughts thank you Harold

 

[Gale Hawkins]

Last year we bought a 1983 310B JD backhoe and it would not pull when using shuttle especially going forward in high range and at first even in low range when hot but in time it would shift OK into forward with the shuttle and not slip in low range

It was milky and I had a rush job so I dumped in two 16 oz cans of Sea Foam and did not seem any noted improvement after working it hard for about 30 hours and it was still milky. Then I added two more cans and forgot about it since I only use high range on the road which is very seldom. The cleaners evaporate in use over time.

The first time I used the Sea Foam with the red dye in it called Trans Tune and the second time I used just regular Sea from since they have the same ingredients. The can states use 16 oz per 4 gallons of fluid.

Not too long ago I checked it and it was clear and I was pushing some snow on the road last week in high range OK even after a few hours of use when it was at full operating temps.

Before we did the bucket flush on the Blazer I used one can for about 200 miles of regular Sea Foam then with the engine pumped out the old ATF and replaced it for about a 97% charge out based on some numbers on the method.

At 70K miles in this new Jasper the delayed hard shift into reverse was back. After running the Sea Foam and then totally refilling with Dexron III ATF the delayed and hard shift into reverse is gone. There is no way of knowing if the Sea Foam helped or it was just all new WM ATF.

 

[shaley]

Does it have a "Turtle/Rabbit" switch on the left hand side of the dash.
This switch controls the speed of the clutch pack.
Make sure this switch is electrically working.

 

[harrydodge]

no switch on dash .thanks for input

 

[tawilson]

When you say it's shifting hard do you mean shifting into gear or shifting from forward to reverse? If shifting into gear then you may need to adjust your free play on the clutch linkage.

 

[shaley]

no switch on dash .thanks for input

Ah, I misread your first post. You has a HSS not a Electronic hydraulic shuttle shift. The Forward N Reverse lever goes to a hydraulic spool valve on the steering column, correct? I think I have the shop repair manual for that tranny.

 

[jimmysisson]

Like TAWilson, I wonder if your clutch is disengaging. Free play should be 3/4" to 1-3/16" per the IT manual. What is yours?
Jim

 

[harrydodge]

I adjusted the clutch pedal. It shifts hard [the lever moves freely] when I move shift lever from f to r without using the clutch pedal ,the guy I bought it from said you use the clutch to change gears not f to r.But when I use the clutch pedal it is slow to engage and is at the top of pedal.Seems like the hyd clutch is not working right.

 

[shaley]

I think there is a hydraulic clutch pack controlled by the FNR lever on that model. There is an adjustment for the relief pressure as well. They had 4 available transmissions for that model. Make sure which one you have. The manual says units produced before S/N UV-25075 do not have the mode command switch on the dash. It could be the clutch pack pilot valve is not working. It is controlled from a small cable attached to the clutch pedal. Do you have a small cable as well as a clutch rod on the pedal.
Here are 2 sheets showing the shift valve. Is this what you have?

 

[tawilson]

Memory fades but I seem to recall a few discussions here over the years and some of these transmissions do need to use the clutch to switch from f to r.