Teamsobaco

Well do I need a new transmission? She acts like I am in 4 Hi/4 Lo
Yes feels like a shift kit and max speed is around 30-35MPH. the linkage is ok and the selector is doing what it is supposed to do. Is there anyway to pull trans codes? When I pull engine codes the OD Off light flashes continually...I assume this means no problem.........The truck was abused overall by PO...Can I flush the system and change the filter or will this just make matters worse? the dipstick does not smell burnt but who knows.....the PO had some shade tree mechanic work on the trans and transfer in the past as there is a sloppy rtv job on all the seals.....

Teamsobaco

Just did a dianosis the OD Off light just blinks continuously along with the check engine...so what ever the problem..it appears to not be "electronic" who can help me on this one?

Cebby

Let me see if I can find it in my FSM.

jimbo74

dont change the fluid or the filter @ this point, it might make things worse...

Cebby

Do you have an FSM? There is a lot of info for diagnosis in there.

The OD light flashing is how it tells you what's wrong.

Normal operation: Blinks twice per second.
Malfunction: 1 time per second. The number of blinks will equal the first number of the two digit diagnostic trouble code. If 2 or more codes, there will be a 2.5 second pause between each.

Teamsobaco

yeah she is flashing 2 times per second..everything is fine supposedly.....is this the transfer or the transmission? I know the are intergrated but I think conventional 4wd and the problem I experience sounds transfer related.....At this point the truck is "dead" because top speed is 35mph. I figure what the heck I will do a trans flush tommorow...is there a filter I need to buy from the parts place? or is this a screen that is cleanable? SUcks..this popped up out of the blue..I think it is hydraulic...not electronic...shoot i don't know I am frustrated.

Cebby

Did you try pulling your EFI fuse to reset the ECU? The FSM says the 4WD system is electronically controlled by the ECU.

Teamsobaco

No didn't try that one....the front hubs are not locked...this happened without even using the 4wd....when I lever shift the tranfer case the 4wd light comes on and the hubs lock in.

jimbo74

dont do the tranny flush! if it is bad, the flush will hurt it nore...


first i would look @ your engine timing htough.... i had a similar problem earlier this week... my cam gear jumped 3 teeth and my truck wouldnt rev past 3k.....

Teamsobaco

no this is not timing related the truck is running better than ever (Engine).....the transfer case/tranny whines like its locked in 4hi/LO..the truck shifts like it has a shift kit...maxes out at 35 mph in 3 rd gear at around 4500rpm

Cebby

What rig are we talking about here? I agree - don't do the flush yet.

You hubs lock in? Do you have auto hubs? (not ADD or Manual)

Teamsobaco

1994 3.slow with all the extra bs like abs

Teamsobaco

JT3VN39W4R0146743

Cebby

OK - under troubleshooting in the FSM:

Page AT-97:

6. Transfer Test

(a) When shift level is shifted from the H2 to H4, confirm the vehicle changes from 2 to 4 wheel drive. If it does not, the transfer is faulty.

(b) When shift level is shifted from the H4 to L4, confirm the vehicle changes according to the shifted diagram. If it does not, the No 4 solenoid, ECM or transfer is faulty.

60+ pages just for the A340H tranny....

Teamsobaco

I found that on page AT-51 but any way...how do I know if it is changing from 4wd to 2wd..do I need to put it on 4 stands and shift it into drive to see if the front shaft is turning?

Teamsobaco

The auto hubs lock in if I shift to 4 hi or 4 low...in 2 hi the are in free,,,but the transfer and transmission act like I am in 4 lo.... do you think the no 4 solenoid in bad or is it the transfer?

Cebby

Are you sure you have auto hubs? I thought those ill conceived pieces were from the 80's. If you have ADD, there aren't hubs at all, but drive flanges. The CV's turn all the time. When you shift, there is a vacuum actuated coupling in the front axle tube that ties the front end to the drivetrain.

I'm no expert in trannies, but it sure seems like a bad solenoid or a bigger prob with the transfer case...

Dirtoy4x4

1994, I am thinking Auto disconnect diff.. I know the 4hi whine you are talking about, however one way to tell is, does the steering feel a little heavy around corners? On all my yota's (97 Runner 94 Truck) the steering will want to pull you around. If your sitting at a dead stop with your tires turned, when you hit the gas it will straighten out the wheels.. Like a front wheel drive car.

You could always pull your rear driveline and see if your truck moves in 2HI, if it does, then you have a problem.

williemon

If it was in 4 hi you would not be limited to 35 mph at 4500 rpm in 3rd gear. Almost sounds like 4 lo gears are engaged. That would really multiply torque like it has a major shift kit, It would whine a lot and would be limited to very slow speeds. The front diff may not be engaged though. So it really is not in 4 wheel drive, but is like a manual locking hub where the hubs are unlocked, but transfer case is in 4 lo gearing. Sounds like its the item that makes the transfer kick in thats faulty and has the transfer in 4 lo all the time.

dragon564

The A340H is a manual shift from 2h to 4h to 4l....the electronics come into play later...I tested on flat dry ground and in 4L with the front hubs locked into 4x4, all I could get is 43KMPH which is in the area of 35MPH So based on what I see here I would say that somehow the truck is stuck in the 4L range