No 3rd Gear-727

[bordin34]

I don't believe that I have a working 3rd gear in my 727. On the highway I am cruising around 50mph and 3000rpm I have 2.45 rear gears and that is about 1000rpm high. What could cause this. The kickdown is adjusted properly and the only problems with the trans are it leaks slowly and sometimes when put in reverse it makes a squealing sound. As far as I know this is the original un-rebuilt transmission.
Dan

[6packCuda]

Figuring out if you have a 3rd gear is easy. Put in manual low, run it up to 15-20mph, pop in into 2nd and run it up to 45-50, then pop in into 3rd. You should be able to feel/hear it shift.

[MEK-Dangerfield]

Is it possible your tach is inaccurate, or do you use an newer after-market tach?



   Mike

[Ck[FIN]]

3rd gear and reverse uses the same clutch plates at the front drum. It is the first drum after the pump. That means if you have problems at reverse and there is no 3rd gear, there could be a leak at the front drum(direct clutch). Front drum uses 2 metal sealing rings at the stator support(bolted to pump housing) and 2 rubber sealing rings at the front drum piston. Other rubber seal is at the piston, other at the drum itself.

Little hard to explain in english, hope someone understands anything. 

What does the oil look like, does it smell burned or it is brown already?

My guess is that one or more sealing ring or rubber seal is broken and you have burned your 3rd gear/reverse clutches.


-Sauli

[73Chally]

I hate to say it, but we can speculate all we want, but you're not going to know anything for sure until you open it up.  When you can, I would just say bite the bullet and yank it out, because no matter what, it will have to come out to fix it anyways.

[tactransman]

3rd gear and reverse uses the same clutch plates at the front drum.

My guess is that one or more sealing ring or rubber seal is broken and you have burned your 3rd gear/reverse clutches.
-Sauli

    The fact that you said you have a squealing sound in reverse sounds like the direct clutches are hurt.

[bordin34]

Thanks, when I put it in manual low, then 2, then D, the rpms do drop each time. My reverse works fine but sometimes makes a faint squealing sound. Could this cause the trans to randomly explode? I might try some Lucas trans fix to see if it does anything at all before it gets rebuilt.

[tactransman]

No,it will not explode. The squealing noise is probably the clutches down metal to metal. If so,Lucas ain't gonna help. 

[Ck[FIN]]

  This is why 727 is a good and strong transmission. The clutches could be burnt a little bit but the transmission still works. It could work 5miles or 5000miles. Lucas might give you some extra miles to that.

[bordin34]

Thanks again.
Tact, if you were rebuilding a trans, would having used Lucas Trans fix make it harder to do, a PITA, or make it cost more?

[tactransman]

Lucas will not effect the rebuild. All Lucas does is if you have a rubber (external or internal) seal that has gotten a little stiff (brittle) it helps to soften it back up a little.

[Bullitt-]

What I don't get here is if it is or is not going into 3rd....Seems that if it IS going into 3rd & had the problem suggested," probably the clutches down metal to metal", then there would be noise/slippage. Is it possible that it's just not shifting out of 2nd?... Would a kick-down or shifter linkage adjustment not be something to try before condemning the clutches?

[tactransman]

That's hard to tell over the internet so that is up to bordin to decide. What I am going by is :
1. A third gear problem
2. A problem (noise) in reverse

one clutch pack applies them both so it is leading to a direct clutch problem.

bordin,one more thing that you can try is to (safely) put the rear up on jack stands and run it through the gears and see if it will go to third off the ground. If you still feel no upshift,then it is probably the clutch pack problem.
 
If you feel a shift,then it could be a linkage problem. (transmissions are easier to get to upshift with linkage/vacuum/sticking valve problems when there is no resistance on the drive train.)

[Kapteenikosmos]

Thanks, when I put it in manual low, then 2, then D, the rpms do drop each time. ......

Doesn't this mean that it is actually shifting into the third?

[tactransman]

Like I said,he has to be the judge of that.