727 Question

[mopar0166]

Thanks for the reply. 

looks like I have some planning to do prior to starting this repair.   Theres no quick fix but information is very valuable in building yet another transmission.

[mopar0166]

would a 833 4 speed be a better option?

[c00nhunterjoe]

would a 833 4 speed be a better option?

Depends on if you want it to be. Both are equally strong and be upgraded stronger.

[Paul G]

If you like spirited driving, and since you are going through 727's I would think you do, a manual has it's own problems. Clutch failure, hammered rear diffs, broken axles. These things are more prominent to failure with a strong manual trans since it can hit the drive line much harder than an automatic can. 

[mopar0166]

I agree,  are you guys seeing a 8 3/4 rear will need some better parts as well if I went with a manual.    The car was built for fun on the street , going to some shows and to enjoy driving it.    If what I'm being told is to stick in drive and go with and automatic, then its really not what I want.   I have a couple jeeps and its awesome to get in them and drive it with a manual.  Ill be talking with the guy who built my current transmission tonight about options.  only concern I have about going to a four speed is the crank wasn't drilled for a manual.

[mopar0166]

Looks like a thrust washer went , which what my guy thinks the left overs in the pan are.  A lot of questions came out of the conversation though.   Like changing the gear ratio finding better internals parts.   Maybe adding a line lock etc.   

I'll have to keep y'all updated

[mopar0166]

thoughts on switching to roller bearing thrust washers

[justcruisin]

IMO an 8 3/4 on the street with a true street tire that doesn't get beat on all the time wont be a problem, manual or auto.
I have run 727's for years, only problem I have had is one broken rear band, probably due to me banging it back to low at full throttle too often. My ride for the last 6 years has been a 440 with around 480hp/727. I have made upgrades to it but at that level a bog stock 727 would be reliable.
I have never had an issue with thrust washers, I would suggest that you check your clearance on your planets, you need to take the slack out of the output shaft by pushing it into the trans (resting the end of the output shaft on the floor will work) then with a dial gauge check the input shaft clearance, if you don't take the slack out first your number will be off, can't remember the spec but you want some - at least .005".

[mopar0166]

IMO an 8 3/4 on the street with a true street tire that doesn't get beat on all the time wont be a problem, manual or auto.
I have run 727's for years, only problem I have had is one broken rear band, probably due to me banging it back to low at full throttle too often. My ride for the last 6 years has been a 440 with around 480hp/727. I have made upgrades to it but at that level a bog stock 727 would be reliable.
I have never had an issue with thrust washers, I would suggest that you check your clearance on your planets, you need to take the slack out of the output shaft by pushing it into the trans (resting the end of the output shaft on the floor will work) then with a dial gauge check the input shaft clearance, if you don't take the slack out first your number will be off, can't remember the spec but you want some - at least .005".

Thanks for the response, the last 727 that was built was upgraded in many ways from stock.  I'm finding new info on how to make a 727 last longer.  My 440 probably puts out similar numbers or maybe a bit more but I don't think a stock 727 would last long.  I could very well be still getting heat issues, I will kow more once it the transmission is removed and up on my work bench.  I took a chance on just adding a big external cooler and upgraded lines to try to keep it cool.  There is some preliminary evidence showing it was running hot, which may have destroyed a thrust washer.  The slack and clearances were set according the 727-service manual that I have.  Those numbers were verified on the internet as well.  I can't tell you that number off the top of my head.  I think the addition of roller thrust washer will be a great benefit, I'm also going to add a fan to the external cooling system and monitor it with a gauge.    No matter what I decide I wanted be able to have fun with the car, If I wanted a cruiser it be much different than a charger. 

[mopar0166]

ill be in Carlisle next weekend looking to see what 4 speed stuff is around.

[John_Kunkel]

thoughts on switching to roller bearing thrust washers

Not as easy as just installing them, machine work involved. Was the thrust washer that failed metal or fiber?

[mopar0166]

It was fiber.  A&A offer a full rollerized kit for the 727, which is machined for the roller thrust washer

[mopar0166]

Our needle bearing kits help reduce the friction in the parts.  Each component is machined to take a Torrington Needle Bearing to replace the stock thrust washers.  Our needle bearing kits have a large advantage over much of our competition.  We assemble our 727 planetaries with all new internal components (i.e., gears, shafts, pins, needle bearings and washers).

727 Complete Kits Include: front planetary, front annulus, rear planetary, steel low/reverse drum with bearing, rear support with bearing and modified steel park gear.

http://www.aandatrans.com/Products/727-Complete-Kit---Planetary-Back---4-Pinion-Steel-Spline-(1962-75-Spline)__22224BKSS.aspx

[BSB67]

Good grief.  Something is not right. Your driving, or your rebuilds or something. I've beat on stock rebuilt 727 with a shift kit at your power level for 10 Years and probably 200 passes at the track.  It was still running fine when I rebuilt it.

[mopar0166]

Ill take the blame over needing to do a rebuild.  I have zero doubt in the build of the transmission it self.   It just needs to be rethinked on surviving more then just cruising etc. 

Ill keep Yall updated.

[c00nhunterjoe]

If they added performance parts, and went strictly by the service manual as stated for assembly, thats probably the problem. If line pressures are up with a shift kit, i would have set the clearance at the minimum. I would bet yours is too loose and the drum is beating the thrust washer to death.

[John_Kunkel]

727 Complete Kits Include: front planetary, front annulus, rear planetary, steel low/reverse drum with bearing, rear support with bearing and modified steel park gear.

http://www.aandatrans.com/Products/727-Complete-Kit---Planetary-Back---4-Pinion-Steel-Spline-(1962-75-Spline)__22224BKSS.aspx

It should be noted that that kit won't work with a fully automatic trans and it doesn't eliminate the fiber thrust washers that failed.

[mopar0166]

thanks for the comments, they both make a lot of sense.   I was told that fiber thrust washer has to be a weak area and should be upgraded to ether steel or rollerized.  I do remember when we setup the last transmission, we didn't spend much time beyond the standard setup to check pressures etc. because it was operating well.  I don't remember the specifics off the top of my head.   I was also told the TH400 transmission use metal thrust washers and that it was an area of question last time it was built. 

Would it be beneficial to find steel thrust washers and also to set the clearances at a min for that setup instead of using the rollerized equipment? 

Thanks

[John_Kunkel]

I have considerable experience building 727's and I don't agree that the fiber thrust washers are a "weak point", I've only seen one failure in over 500 builds and I believe that was the builder's fault i.e. too much end play in the front setup.

[mopar0166]

Thanks for the comment John,  I have noting all the great advice for if and when I decide to do another 727 build.  Not to push negatively on the subject, but for my own education, why is a fiber thrust washer used vs a metal etc? 

When I drop the transmission completely out , ill make sure to make a new post and take a lot of pics as well.  I will also look over the manuals that were used during the build maybe their is a better one for performance builds. 

Thanks again 

[John_Kunkel]

The metal tanged thrust washers in the gear train are one thickness only and the endplay is set with a selective thickness snap ring, the large diameter fiber thrust washers used between the clutch drums are selective thickness and this is used to set the end play in the front group. If the end play is too loose the drums can hammer on the thrust washers and cause them to fail.

Another small fiber thrust washer is located between the input and output shafts and this, too, can fail from too much end play but a bronze replacement for it is available and often used even in stock rebuilds.

[mopar0166]

Thanks for the comments,  so would say in a performance setup the end play should be on the tighter side? 

The books I had on hand were the Torqueflite A-727 Transmission Handbook: How To Rebuild or Modify Chrysler A-727 Torqueflite and Jeep Dodge Torqueflite A727 / A904 Transmission Rebuild Repair Manual by ATSG: 1962-2002.


Is there a better manual option?

[John_Kunkel]

The FSM for the specific year of your trans is a better manual, the others cover too wide a range.

[mopar0166]

Thanks John,

Any opinion on planetaries and 4/5 clutch drums ?

[John_Kunkel]

The common consensus is that the 4-pinion planetaries are stronger, but the weak point isn't the pinion count, it's the splines in the aluminum front planet carrier. Surprisingly, the 3-pinion front planetary is actually stronger in the spline area than the 4-pinion so don't turn up your nose at the 3-pinion planetaries.

I wouldn't use less that 4 clutch discs in either drum, 5 is OK but not really needed IMO.