lost power at speed

[ukexplorer97]

Trying to diagnose a problem with my 97 explorer. Any suggestions appreciated ...

Explorer lost power on the motorway - engine still running fine just no drive to the wheels and a coast over to the hard shoulder. After restarting was able to get the car moving but it was stuck in low gear with OD light flashing which I gather is 'limp home' mode. Stuck a code reader on it this evening - some unrelated errors reported on the ARC system and code P1729 indicating that 4x4 switch was faulty - surprised not to see any codes stored related to the transmission/tc though. 4x4 and 4x4 lo lamps light ok, no flashing, but definitely no thump from the shift motor when engaging 4x4 lo. Is the 4x4 switch issue likely to be related here or a separate issue?

(Noticed that -ve battery terminal appears to have worked loose around the same time).

Thanks,
Neil

 

[SB98UKexplorer]

disconnect the terminals, clean them up and re connect them after 15min to reset everything and go from there

 

[ihpj]

Glad no-one was hurt/injured and she coasted to safety. I'm sorry but I have no idea why she would have done that other than to suggest maybe it's your auto box?

 

[ukexplorer97]

Thanks for the replies. Cleaned up and secured the battery cables and allowed it to reset but OD flashing returned after a short distance. Will check the state/level of the trans fluid next. Breakdown guy suggested maybe the torque conv went bad but bit reluctant to just start replacing stuff.

 

[kevin p]

Have you tried adjusting the brakebands on the gearbox?

 

[janolsson]

couple of things to check
1 pull the panel of to check the state of the switch
2 check the wiring to the shift motor as there are connectors there and in the chassis rail that may have water ingress
3 check the fluid level in the transfer case (doesn't share the same fluid as the box)

I would think after clearing the codes it doesn't shift into 4 lo then the issue is shift motor or transfer case issue or switch rather than transmission.

Now i'm assuming you are trying to put in 4 lo with transmission in N and foot on the brake!!

 

[ukexplorer97]

Some further symptoms/findings:

- Took off switch motor and watched it while selecting/deselecting 4x4 lo; all moved as expected. 4x4 lamps and GEM readings for 4x4 selection all look ok. Still no clunk when fitted though.
- TC and Transmission fluid levels ok.
- Some fluid leaking at TC/Rear prop (very recent)
- Driving it:
- Is changing up gears but not as smooth as normal; feels like a bit of delay/slip
- Sounds like a high pitched whine from somewhere near TC/transmission (I think).
- OD flash kicked in somewhere around 20/30mph and the P1729 code reappeared at the same time.

Anything else obvious worth checking or is next step opening up the TC?

 

[ukexplorer97]

having read through some of the forum threads on common issues with this transmission I'm wondering if my cheapo ebay OBD tool is really getting the codes from the transmission. Can anyone recommend a scan tool & software that they know works good with this auto box?

 

[ukexplorer97]

so ... finally got the transfer case off. Removing the nut on the output shaft has defeated me opening it up (will need to get a socket to fit.) However I can hear something metallic loose and large clunking around inside.

From some searching through the transmission forums I'm guessing I might be hearing a broken shift fork rattling around.

Any ideas what the going rate is for a second hand TC is from a scrappy? Trying to work out if it's worth trying to repair and rebuild this one or whether taking a punt on a second hand TC is a cheap option anyway.

 

[ihpj]

Get in touch with ChrisQ sharpish! He is breaking two Ex's as we speak.

 

[ukexplorer97]

Thanks ihpj, Chris kindly confirmed that he had one available but I'd just managed to find one at a local scrapyard that morning. Fixes my 4x4 lo shift and 'limp mode' issues nicely but need a few more miles on her to convince me that this was indeed the cause of all my grief.

 

[ukexplorer97]

Just to close off for anyone having the same symptoms and coming across this thread ...

A socket and breaker bar didn't budge the nut on my broken transfer case; needed a impact wrench to shift it. (Cheap 240v CEW1000 worked nicely)After lifting off the top half sure enough there's the shift fork broken in two with the broken arm rattling around loose.
The shift rail bore's don't look to out of round to the naked eye but there's a fair bit of wiggle backwards/forwards. I think repair of the Mg case is a bit beyond me - would be interested to hear if anyone here in the uk knows of a machine shop that can rebore/sleeve these? As per various threads on the transmission/TC forums, Omegamachines offer remanufactured case halves but with customs/core charge might work out pricey for getting in the UK.

Will stick with salvaged replacement for now - going rate seemed to be around £250 delivered online with some online scrappies looking for as much as £450 As ever, trawl around local scrappies was cheapest and was able to pick one for around £100.

just happy that I've pinpointed the cause even though it turns out that it wasn't due to the wife's driving after all