Automatic Transmission Intermitently Fails to Shift into 3rd Gear

Maintenance/Repairs
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1

I have a 1993 Isuzu Trooper with 242K miles on it. A couple of weeks ago the transmission started failing to shift into 3rd gear. I would act just like it had been put in neutral after it shifted out of second gear and the engine would rev up. My mechanic told me it needed a new transmission but the cost was more than the vehicle was worth. I retrieved the vehicle from the shop and drove it around in 2nd gear for a couple of days. Then I forgot to put the shifter in 2 and put it in drive. About 10 minutes later it dawned on me that the truck was shifting fine. This lasted for about a week and then it started having the problem again. I drove it in 2nd for a little while and it is fine again. Any ideas what might be going on and how difficult it would be to fix?

2

This is an electronically controlled transmission so you might run the Trooper by a transmission shop to have any trouble codes read. It may be a long shot but you might just need a sensor, shift solenoid, or pressure regulating solenoid. Therefore post back any codes that turn up.

This truck has a 4L30-E transmission so Transman618 should know something about it and post back with good or bad news.

3

Very doubtful it would be an electronic issue. The neutraling indicates that 3rd gear is being commanded but the 3rd clutch is just not there. With 242k miles, yea, its worn out and tired. I would have also recommended a transmission in this case,

transman

4

I’m not faulting my mechanic for recommending a transmission. I’m just curious as to how it got well and whether it is likely to stay well for a while. It has been running fine for about a week now. No slipping and shifting perfectly. Could a worn out clutch start working again? I was hoping for some sort of valve that had gotten stuck and then came unstuck. If a clutch can stop working and then start working again, then that could be what it is. If so, then junking the truck is the only option that makes sense considering it is only worth about $1500 (been used for a work truck and pretty trashed)but if it is something fairly simple/inexpensive, I would probably fix it.