Mahindra 2638 HST quit.

[cbcbass]

My tractor was working fine all day and on my final load of dirt, it was only moving with 4 WD. Hst would not go forward or reverse. Checked to make sure PTO was off, nothing. Bucket works, backhoe works, but will not move. I did a search and could not find a thread relating to this problem. Anyone have any advise?

 

[K5lwq]

First welcome to TBN!

If I understand, it will move with FWD Engaged? If so maybe check air pressure in rear wheel if they are loaded. There has been several times the wheels will spin inside the tire. Increasing air pressure usually fixes the problem.

 

[cbcbass]

I guess I didn't really clarify the problem. With nothing in the bucket, and 4WD disengaged, the tractor will not move forward or reverse. Something wrong with HST.

 

[LittleBill21]

I guess I didn't really clarify the problem. With nothing in the bucket, and 4WD disengaged, the tractor will not move forward or reverse. Something wrong with HST.

if it moves in 4x4, then its not a hst issue most likely.

 

[duffer]

I suspect you've already checked these, but if not, here goes:

• Check your gear range lever on the right side of the seat to make sure it hasn't "slipped" into neutral. Mine does occasionally
• Check your pedal linkages under the deck where the pedals are in case one came loose.
• Check your hydraulic fluid level

With the tractor working as it should all day, and then suddenly nothing, I suspect it's something simple. If you had a major hydraulic issue, it would show up in the bucket, 3 pt operation, etc. There's only one hydraulic pump on the tractor.

Keep us posted.

 

[cbcbass]

I have checked gear shift and it is in gear. Hydraulic level is good. Checked linkage and both pedals operate. Talked with service person at Mahindra in Chattanooga, Tn and they said there is a cotter pin allowing pedals to engage transmission and it may have come out. That will be my next look. Will post back with results.

 

[K5lwq]

Did you check rear tire pressure?

 

[cbcbass]

Did you check rear tire pressure?

Tires are fine. Rear tires won't even attempt to move. It is a transmission problem.

 

[K5lwq]

Real good. More often then not rim slipping in the tire gives people the illusion something is wrong with transmission. Especially when it will move in FWD. Hopefully it will be something simple.

 

[ericm979]

It's unclear but it sounds like you're saying it moves under power in 4wd but not in 2wd. If that is the case the problem is not the transmission or HST pedal linkage or range selector. Power to the front drive shaft is taken after the main and range transmissions.

It'd be something like a broken rear differential or the big reduction gears between the diff output and each axle. If those broke while operating you'd probably hear or feel it.

K5lwq's post about the rear tires rotating in the rims is one to pay attention to. Mark each tire and rim so you'll see if the tires are spinning inside the rims.

 

[cbcbass]

Update. Spent some time under the tractor looking at linkage viewing how they engage the transmission. They all look good and turn the shaft going into the transmission. Added fluid until sight glass was half full. Started the tractor and tried to back up or go forward and nothing. Lifted the front end with the bucket and engaged 4WD. Pushing the pedals made the front tires turn both forward and reverse. Put it back in 2WD and pushed pedals. The engine would labor but no movement so, it looks like the problem is inside the transmission. Will take another look under the tractor tomorrow before calling the shop. I hate being work stoppage. BTW: I did not hear any gears clank or make any noise before the failure.

 

[K5lwq]

Have you tried it with the Differential lock engaged?

 

[ptsg]

Maybe it broke all the bolts holding the ring gear in place? Or something in the diff let go.

 

[cbcbass]

Have you tried it with the Differential lock engaged?

I tried the differential lock with no success. I have called the dealer to come and pick it up. I don't have a clue how we will load it. lol

 

[cbcbass]

Well, they picked up my tractor and said it may be a month to four months to get a new transmission. So much work to do and no tractor to do it.

 

[3gunr]

That sucks , I have the same tractor with 380 hrs , hope it stays strong. I also have a lot of work to do coming up. Good luck and keep us informed. Have they actually diagnosed the problem ?

 

[duffer]

That sucks , I have the same tractor with 380 hrs , hope it stays strong. I also have a lot of work to do coming up.

I have the 2538, predecessor to the 2638 (same drive train). Had it since 2017, got 1400 hours on it, and not one problem.

In fact, this is the 1st significant problem I've seen on this board for the 2538, or 2638 since 2017. Rarely do you hear of any problems at all with them.

Hopefully this is a one-off for the OP.

 

[cbcbass]

I went to the dealer and the tractor is just sitting there. They said there work load was backed up. hopefully, they will look at it this week. It is no skin off their nose. lol

 

[gatractorman]

Have you had any updates? I have one with exact same problem and my bolts thru ring gear carrier to ring gear are all broke or backed out! Does not appear they were long enough to start with!

 

[cbcbass]

I talked with them yesterday and they finally got it into the shop. No status when they will break it down. Will update when I know more. Did you get yours from Anderson Feed in Dahlonaga? I am also in Cleveland GA.