Codes P0734 & 0171 last week. From my recent experience with my former Jeep, I knew this was not good. Brought it to AAMCO, as they did a good job on the Jeep, which had the same code. Here is the diagnosis : Probably due to a clog in the tranny cooler, the heat fried the torque converter and a few other parts internally. New torque converter, rebuild on valve body, and, after flushing the cooling system, that can be preserved. Interesting to note that several of the internal replaceable parts are either Denso or Borg-Warner, so the cost is substantially less with no compromise in quality! Side benefits : will no longer have a leak, will have 4-low (attachment was buggered, repair for free), install new front prop shaft (I was going to do that..), and good inspection of rear prop shaft - looks in good shape! Bad news : $3900.00 USD. 12/12 warranty and peace of mind : priceless!

 

Never let them determine what is wrong with your tranny. A 734 state that 4th gear is out of ratio 171 states that bank 1 is too lean. Both these codes will come up as your MAF is failing.
I sure hope you didn't fall for that crap. If you have any questions, get back to me.

 

Their stories get more complex as the vehicles have improved.

 

I am firmly convinced that almost every tranny shop is run by actual thieves.

My volvo tranny went into limp mode, 2 tranny shops said it needed a $5k tranny. Had a used one put in by my mech, and it didn't fix it. Turned out I needed a new transmission computer. Which I got for $40 on ebay and swapped in about 20 mins.

I doubt I'll ever walk thru the door of a tranny shop again.

 

My error on code - that was the previous go around, when all 4 O2's & MAF were replaced to get it inspected. This was Torque Converter Clutch Not Locking or some such description. Too late anyway, as the torque converter was fried.

 

That gives us nothing to work on, go to your local parts store, have the codes read for free and get back to us with the actual fault code numbers not t/q or some such thing.

 

For a lot of owners, the tranny shop is a place to be feared. Most Discos are in the boneyard due to chronic overheating, and a u-pull-da-parts tranny is like $125 near me. $100 extra for them to pull it. Some boneyards even sell a short warranty to go with it (like 6 months).

Keeping Rover running on the cheap challenges constantly.

 

It's my understanding that the DII tranny is one of the strongest components on the truck. And it'll take a lot to break it down. If my tranny failed I would have no qualms about picking one from a boneyard.

 

It is if maintained.

 

The torque converter clutch was not functioning, and there was scorching on the motor side of the converter; two valves in the valve body were toast. The transmission cooler was clogged - had to be back flushed several times to provide line pressure up to spec, at least I didn't have to replace that! The bracket securing the 4-low/high to the t-case had two stripped bolt holes which are being tapped (for free by the shop). This was a surprise, but I had never engaged 4-low so there was no way I could have known this. Being a fairly competent 'shade tree' mechanic who's experience is mostly with Jeep's, I think there was no way I could have determined these issues without dropping the t-case & tranny, something I can't do at home! The bottom line to me, in view of the prior posts here, seemed to be that if Disco's have chronic overheating issues, why would you replace the tranny with one from a recycler? I know the ZF units are strong, but without proper fluid flow and cooling, it would be just delaying the inevitable. At least now, after a comprehensive rebuild, and correcting other issues that would not have been, I feel good about what I committed to.