Need Tranny Swap Info

[ewoss3]

Does anyone know how well a chevy turbo 400 will work behind a 78 dodge 440. I have had the Dodge automatic rebuilt 3 times now and it keeps blowing. I saw a conversion kit for putting a chevy turbo 400 behind the 440 and thought this might be a great swap. The kit is by TCI and seem to be a complete set-up minus the tranny.

The truck is used to haul a Kubota L3010, boxblade and backhoe attachment on a dual axle trailer. Everyone has said that the dodge tranny is up to the task but so far it has just proved to be the weakest link. I have had 3 failures in 2 years, with me babying the last 2 rebuilds.

The questions are
Who makes kits for this swap?
What is the apprx cost?
Will the turbo 400 be up to the task?

Thanks for your help

 

[Von]

Rob, I don't know if the turbo 400 is up to the task, but I do know that it is rated to handle 1000 HP. So I think it will work. Just get a good tranny with all the latest upgrades and a large oil cooler. Good luck!

 

[wallysue]

I have a 74 3/4 ton Chevy service truck with a 454 and turbo 400. The original TH400 lasted over 100,000 miles and failed only when the oil mixed with the gear oil in the aftermarket Doug Nash overdrive attached to it. I didn't pull a trailer much but the truck with the body and tools on it weighed over 7000 lbs. The TH400 was a cheap fix, less than $200 on an over the counter rebuild. I have heard of guys paying better than $1,500 to get one of those newer automatics with overdrive built in fixed. That's scary.

Your truck probably has the 727 in it. I always heard those were pretty much bullet proof. Did you get a swap or did they fix your original? Maybe something is up with your case or valve body if it wasn't a swap.

 

[JimMc]

There were two 727's, the 727A and 727B. The B was built for the 426 hemi. If I remember correctly, a complete rebuild kit is all that's needed to upgrade. I put a 727B in my 1970 Charger, but got it complete from a racing buddy who blew his hemi.

 

[RobertN]

I would find another tranny shop. The Mopar 727 tranny is about as stout as they come. The 440/727 was used in motor home applications for years. It has also been put behind hot Hemi's and 440's, cranking out major HP.

What's been blowing on this tranny? What was the mean time/mileage between failures? Did the same shop work on it each time? When it was rebuilt, did they check out the torque converter, and the tranny cooling system?

I'm really curious, because the 727 is a sturdy tranny. Either it isn't being rebuilt right, or the shop is overlooking a problem in the casting or something.

 

[ewoss3]

I found my 727 in the recycle yard and had it rebuilt while doing the motor swap. The first was a standard tear down and re-build, it lasted for 13 months and 1500 miles. Took it back to the original builder and it had grenaded the large ring at the back of the case, which in turn trashed the tailshaft casing. The shop got a second case and rebuilt it for another $875 including the upgrade to the heavier ring for service trucks. This lasted for 8 month, then the tranny started slipping, lost drive then 2nd and managed to get it home and on the trailer in reverse(was only one mile away). I took it back to the same builder and the did another band job on it($675). This has lasted for 6 months and now it is slipping again(now I'm sure I don't want to rebuild it again).

The first rebuild I installed with a new torqe converter, replaced all cooler lines and installed the largest cooler and fan I could fit. The fluid is checked every time it is driven and when pulling a load it is manually shifted(reccomended by the builder). The builder has inspected the case and installed a new torqe converter each time in the rebuild.

I really don't think he is trying to jerk me around and he comes highly reccomended by the local municipal and several friends who tow and race with his trannies.

At this point I figured on trying something new since I have tried most everything else. This truck is a 1981 1 ton dualie with 35,000 original miles and only gets driven between our mobile home parks and for hauling dirt on the dump bed. The 440 and 727 are less than 3 years old. The 440 has a medium rv cam installed so I don't think I am applying too much power

sorry for the long post but wanted to give as much info as poosible

 

[Anonymous Poster]

Re: 727 or 900

Sorry to be threadjacking here, but how does one identify a 727 from a 900 mopar tranny?
I have a couple brand spankin rebuilts complete with torque converters from when the police fleet switched over to all Fords, and would really like to know the method of identifying the model.

 

[s1120]

I hate to say this, but you eather have a bad rebuilder, or yoou got a cooling problem with the truck. The 727 is as strong, if not stronger then the TH400. Save your money, I think you willl tost the 400 also. Find a rebuilder that works on drag cars in the aera. Something is wrong. Get a pro to c heck it out.

 

[Anonymous Poster]

If I remember right, the 727 has a clipped corner in the pan. Not quite a perfect rectangle. On the other, it seems to me that someone is not rebuilding correctly. I've had many Dodge pick up trucks and never had a problem like mentioned here. I've worked all of them way beyond stated specs. I did see however, a problem with one Ford dealer who kept rebuilding the same old tranny only to blow shortly later and rebuild again. The dealer WAS rebuilding to spec. Problem was, not beefy enough for the job. That same transmission was brought to an outside source, where this guy changed some ball bearing placements in the valve body. Tranny is still working 6 years later. This happens to be the town highway dep't Ford F350 4 X 4 one ton dump and plow. Truck has many different drivers also. Sometimes I guess you just need that person who can rebuild it to what is needed.

 

[ScottAR]

What is the rear diff gearing and tire size?