727 trans issue

[cerberusiam]

The heat exchanger is a possibility for getting water in the trans but it usually goes the other way since there is more pressure in the trans system than the cooling system even at an idle. The anti freeze in the fluid should create a nast sludge that will show in the pan immediately.



You will have to trace the lines and find which are which on that trans. I don't remeber off the top of my head which one it is. Just be careful if the trans is starting to go. Finding one of those cases if it kills it will be a painful process.



The fluid level should be above the filter and its mounting base at all times or you will have some air problems in the fluid. I doubt the ripped filter would cause it unless fluid level was extremely low. The ripped filter may be a symptom of something else though and it has let contamination into the gallerys and clutch packs.

 

[1stgen4evr]

Finding one of those cases

I know that they are a bit rare but I have a complete 727 in the 89 that I will be removing. It can be test driven as of now. I know of a take out from a crash that has only 40k miles on it.



1stgen4evr

James

 

[btoscano]

I've dropped the pan 4 times now and each time there is a shiny brass colored tail in the pan. The magnet is staying clean. I've put about 4-5 gallons of fluid thru the system and the fluid is looking fine, but the symptoms persist. It was 10 hex head bolts to lower the valve body, the TORX bolts seem to hold the valve body together.



Thanks,

Brian

 

[cerberusiam]

That much brass is a classic indication of a thrust washer eating itself up. Unfortunately there is no good way short of tearing the transmission down to pin point which one it is. If you have no symptoms of failure and no new noises or erratic operations it will probably run for a while but it sounds like it is on borrowed time. It would probably be a good idea to start looking for a replacement or planning a rebuild. Good luck.

 

[btoscano]

What years/models interchange for a possible used 727? Will 727's from other Chrysler vehicles work? If the rear axle ratio is different would I only need to swap the speedo gear?





Thanks,

Brian

 

[btoscano]

Is there a "normal" lifespan for these before they require a teardown and rebuild?



For example, on MB transmission's that I'm familiar with many fail around 175Kmi unless they are largely highway driven and then they can go 300Kmi+.



Thanks,

 

[cerberusiam]

Lifespan is wholly dependent on use, maintenance, and driving style. If the vehicle is driven with an eye towards longevity they are quite capable of going 300k miles with no problems. If you feed what the CTD is capable of generating and use it frequently you will be rebuilding it. We have a medium duty engine hooked to a light duty transmission and there is no way around the physics of the equation. Another note on longevity of rebuilds, in addition to the above you can add the skill of the rebuilder and the quality of parts used.



The case used in the early 1st gens was a one off production to match the engine adapter and was only built for about 2. 5 years. You have to use the case from a CTD as the gassers had different bell housings. If you get a case that had a different rear end behind it you can just use the gears from your setup.

 

[btoscano]

One other thing, very often when I'm at a stop light, in drive, with foot on brake, the oil psi drops to the 2nd mark (of the 4 inner marks). Shifting to netural and it goes back up... Is this normal?



ARe there thrust washers or such in the torque converter that may be the metal I'm seein in the pan?



Thanks,

 

[cerberusiam]

The oil pressure dropping could be the rpm dropping while in neutral. These gauges are virtual so there are several things that can interfere. The best way to make sure is put a manual gauge on it.



I believe there is a thrust washer in the converter also. Not positive as its been a while since I cut one apart.

 

[btoscano]

Thanks.



What should I expect to pay for a rebuild?



Used trannys are listing between $700-1000. Does $850 seem like a reasonable price for a junkyard trans that works?



Is there a difference between 4x2 and 4x4 models?



Thanks,

Brian

 

[cerberusiam]

Yes, there is a difference between a 2x4 and 4x4 trans. The 4x4 has a shorter output shaft and no tail housing. If that is all you can find you can combine the two and make one but the trans will have to completely dissassembled to do it.



Your best bet is start calling local shops and places like DTT, ATS, and Goerands to get a feel for prices. You need to specify it is behind a Cummins so they know what to do to rebuild it and if they don't do anything different or don't want to tell you, run don't walk away. Most trans shops don't want to deal with the diesle trans and the warranty problems the cause for the inept. If your lucky you can find a local shop that will be reasonable and do a good job. As a guess a good rebuild should run $1500 to $1800 with a converter. You should just get the trans rebuilt and tweaked and get a better aftermarket converter. Good luck.