Lockup Converter in Older 727?

[Powerflite]

I am wondering if it is possible to use a lockup converter in an older big block 727 trans. What all would need to be swapped to make it work? Which year 727 transmissions came with lockup? Also thinking of swapping to the lower gearset at the same time. Thanks.

 

[Bulldozer]

read here, this should answer some of your questions

[ame]http://wagoneers.com/FSJ/tech/Transmissions/727TorqueFlightinformation.pdf[/ame]

 

[fishy68]

It may be possible but it'll probably take everything in front of the front planetary gearset and a lockup valve body to make it work. For that reason, IMO it'd be best to just find a complete lockup 727 and rebuild it.

Where do you plan on getting a low gear set? As far as I know they never had a low gear set in a production 727 and aftermarket sets are big bucks.

Also, you didn't say what year your "older" trans. is but 70 on back used a 1/2" wide front drum to pump bushing. 71 and up had a 1" wide bushing that provided a lot of stability and longer life.

 

[Powerflite]

I am trying to build this trans with a short tailshaft from a van. These big block van transmissions are not very easy to find so that is why I am asking. But it sounds like I will need to obtain a newer transmission and swap the guts into the van. So what years came with lockup? I assume that I could use a small block 727 lockup trans to pull the guts out of equally well, is that correct?

I would also assume that the lockup portion has nothing to do with the tailshaft so that I can swap in the lockup frontend and keep the short tailshaft?

I am expecting to pay for the aftermarket lower gears, unless by some stroke of pure luck the 999 stuff are made the same as the 727 (yeah, didn't think so).

 

[fishy68]

I am trying to build this trans with a short tailshaft from a van. These big block van transmissions are not very easy to find so that is why I am asking. But it sounds like I will need to obtain a newer transmission and swap the guts into the van. So what years came with lockup? I assume that I could use a small block 727 lockup trans to pull the guts out of equally well, is that correct?

From everything i've read they started production in 78. Not sure if they made them all the way to the end of production in 90 or not. I have been rebuilding torqueflites (mainly 727's) for 30 yrs. and have yet to actually see a lockup 727. I've read they made them but they must be really rare. Small block internals would work if the output shaft is compatible but they made 3 designs of output shafts in the area of the front end of it that mates up to the input shaft so you have to make sure and get stuff that mates up.

I would also assume that the lockup portion has nothing to do with the tailshaft so that I can swap in the lockup frontend and keep the short tailshaft?

See my above comment

I am expecting to pay for the aftermarket lower gears, unless by some stroke of pure luck the 999 stuff are made the same as the 727 (yeah, didn't think so).

LOL.... Now your dreamin!

BTW: if this is going into a van have you considered building a A518 instead? IMO it'd be much easier and quite possibly cheaper to do and you'd have overdrive which will lower your RPM's a lot more than a lockup converter. You probably wouldn't be able to put a low gear set in it but with overdrive you could run lower rear gears and still spin less rpm in o.d.

Uhh nevermind that idea. I just noticed you said it's a big block. They make adapters but their costly.

 

[Powerflite]

Wow, I didn't know they were that rare. I expected to see them more on the early 80's Diplomat cop car etc, but I guess most of those would use the 998 or 999.

I am building this trans for my '68 383-S Barracuda. I don't want to mess with the sheet metal at all on this relatively rare car, so this is the only overdrive option that I will consider. The short tailshaft is required for the gear-vendor in an A-body to keep the driveshaft long enough and prevent vibration issues.

 

[Powerflite]

Other information I found is that *at least* the input shaft, reaction shaft, valve body, converter, output shaft, driving shell and possibly the front clutch drum are all specific to the lockup version. It may be possible to use the older output shaft, but I'm not sure at what point old stuff can mate up to new stuff. So it sounds likely that I would need to use the whole setup and get a matching output shaft in the 8" length. Nuts.

I also found this statement on moparchat:
"The lockup 727 was introduced in '78 and that was the only year that a lockup 727 was available behind a big block. It was used behind the standard performance 400 in B body wagons and some C bodies.
This one-and-only big block lockup trans carries the P/N 4028824.
Evidently it didn't fare too well because a service bulletin was issued to replace it with a non-lockup 4058114."

I'm not sure what the main issue with it was being the 1st year of the lockup, but because of the rarety and likely reliability and conversion issues, I am going to forget about lockup for this trans.

Thanks for all your help!

 

[fishy68]

Other information I found is that *at least* the input shaft, reaction shaft, valve body, converter, output shaft, driving shell and possibly the front clutch drum are all specific to the lockup version. It may be possible to use the older output shaft, but I'm not sure at what point old stuff can mate up to new stuff. So it sounds likely that I would need to use the whole setup and get a matching output shaft in the 8" length. Nuts.

I also found this statement on moparchat:
"The lockup 727 was introduced in '78 and that was the only year that a lockup 727 was available behind a big block. It was used behind the standard performance 400 in B body wagons and some C bodies.
This one-and-only big block lockup trans carries the P/N 4028824.
Evidently it didn't fare too well because a service bulletin was issued to replace it with a non-lockup 4058114."

I'm not sure what the main issue with it was being the 1st year of the lockup, but because of the rarety and likely reliability and conversion issues, I am going to forget about lockup for this trans.

Thanks for all your help!

No problem. I gotta feeling you'd have a real hard time mating up the parts necessary to make it work. Since your adding a gear vendors I wouldn't be concerned with lockup anyway. The lockup will barely drop it 200 rpm where-as the gear vendor's will drop it several hundred rpm.