no reverse in my 727

[pishta]

Bought a 727 that was "kitted" by a friend of mine. I know, I should have, but it was a package deal. Anyway, it has no reverse. I tried reverse and there is no bog or difference in the R or neutral. The kit was a B/M transpak with no other modifications. Could he have misplaced a check ball or something? I did a 904 a while ago and remember I used the wrong seperator plate once and had no function at all. could I get a junkyard valve body and slap it in just to get it moving? and does a 904 differ from a 727 in valve bodies? Thanks

[The Dartman]

Sounds suspiciously like my Dad's car.

He has a manaul valve body kit in his 727 that I feel is solely responsible for his transmission problems. When his reverse went out, it broke the tang off of the first and reverse band.

His car also has a problem when it's cold, or when you don't slam the gear, that the car sporatically locks up and tries to engage first and reverse at the same time. Our transmission man said this was the result of a shifter being out of adjustment. I personally don't think so since this car had a junk B&M shifter that did it however it was adjusted, and then a Hurst Pro matic II that did the same thing only slightly less often. This was no matter how it was adjusted.

Dartman

[polarapete]

When you remove the pan you will probably find that the rear-most band is broken. This band applys in low and reverse and commonly breaks after a few million applications from metal fatigue.

Unfortunately, you cannot replace it without a complete disassembly of the transmission.

I once bought a perfectly good '71 Fury wagon with good interior & body, strong 360 v-8 and no reverse for $50.00. After I rebuilt the transmission with new bands, clutches & seals it served as the family hauler and tow vehicle for the race car for five years. And I sold it for $1,500.00 with the race car trailer as a package deal when the rear window motor quit, I didn't want to play with that!

Sorry there is no magic cure. You will just have to take it apart and learn what makes them tick.

[PLUM_72]

The lo/rev band apply lever strut may have been inserted incorrectly. This piece looks like a flat piece of metal about 1 inch by 1-1/2 inches. The short sides of the apply lever should rest on or touch the band itself and the apply lever. If Im not mistaken the B&M kit modifies the rear servo which would require the removal of the apply strut and allow the band apply lever to be rotated out of the way.

[pishta]

I got low though, would that not work with a broken band? I understand that reverse requires about 300 PSI also as others need only 75PSI. Im wondering if my pump is bad? I hope not, that trans is shoehorned in there!

[6 packin]

I bet you dont have drive or high! Reverse and high are in the same drum or clutch pack right?

[amxauto-x]

The reverse went out on my van w/727 and it still had all forward gears. Also did that on the Ramcharger on a real cold day. He said the band broke.

[deadhorse66]

Originally posted by 6 packin
I bet you dont have drive or high! Reverse and high are in the same drum or clutch pack right?

Yeah, but the clutch pack probably isn't the problem.

R=reverse drum and low/reverse band applied
D1=direct clutch only applied
D2=direct clutch and kickdown band applied
D3=direct and reverse clutch applied
Low=direct clutch and low/reverse band applied to allow for engine braking
2nd range=same as D2, but prevents shift to High, with no engine braking

pishta, check to see if you have engine braking in low range (with the shifter in the "1" position). If it doesn't act just like a manual tranny when you let off the gas, the problem is low/reverse band related. You can see that band is only used in low range and reverse, and is the common friction member in the two ranges. If you have two ranges not functioning properly and a common element between them, you pretty well have the problem isolated.

[kdoghouse]

the only time the low reverse band applies is obviously in reverse and MANUAL low. Thats when you pull the handle down to 1st. It is used then for more holding power because they are assuming if you put the trans in manual low your going to be accelerating hard. Other wise only the one way clutch is used. This explains why you have all forward gears even manual low and no reverse. You just dont have the extra holding power in manual low without the band.

[pishta]

Ok guys, I guess I have no band, or band strut. I bet it is the strut. I can do that with the trans in the car right? I sure hope so! I know exactly what it looks like. I think I had to buy one for my 904 rebuild also! Ill look tomorrow. Glad I bought the pan with the drain in it!

[451Mopar]

Like everyone else said, low band. I broke one in my truck many years ago and some deal, no reverse but it worked fine in drive.

[John Kunkel]

To isolate the rear band, place the shifter in 1st and accelerate to about 20 mph and throttle back to idle. If the car noses down when the throttle is released, the band is applying but if the car just free wheels like it's in Neutral, the band isn't applying.

[amxauto-x]

So, John, if the car doesn't even move until the engine revs up to about 2,000 and then moves off and is in 2nd. Then shifts once into 3rd, then what could be the trouble? That happened to my 904 back in the mid '70's and don't remember what it was. The selector was in drive. As I remember there was no reverse either.

I know the sprage clutch broke and then I bought a B&M tranny. But it kept braking the sprage also. So I put the internals into another case myself [with the shop guy surpervising] and it worked just fine.

[pishta]

OK, pulled the pan and found the rocker that works off the annular piston just hanging there, not even touching the bottom of the piston. I thought the piston was stuck up in its bore, but it looks like the strut was not keeping the rocker applying on the band. I then felt up in the trans and couldnt find the point on the band that the strut would act on. Maybe it is broke (duh!) maybe it just slipped off the strut (hopefully) Ill look tomorrow after I sop up the pool of fluid that rained down on me when I cracked the valve body. What a messy job!

[amxauto-x]

pool of fluid that rained down on me

That's why they make drain pans, but why don't they make ones about twice as big! I'm always spilling fluid regardless how carefull I am with the pan! A drain plug would be in order while you have it off.

[1972roadrunner]

Originally posted by deadhorse66
check to see if you have engine braking in low range (with the shifter in the "1" position). If it doesn't act just like a manual tranny when you let off the gas, the problem is low/reverse band related. You can see that band is only used in low range and reverse, and is the common friction member in the two ranges. If you have two ranges not functioning properly and a common element between them, you pretty well have the problem isolated.

hmm, thats interesting...all of a sudden one day my dads '93 chevy silverado wouldn't downshift into 2nd or 1st when i tried to manually downshift...it still doesn't. when it's cold, it'll really hit hard and shake the entire freakin dash when it goes to 2nd from 1st...so i usually take off in 2nd when it's cold. it does actually start from 1st or 2nd when i pull the shifter down, but it won't downshift like my 727 in my roadrunner... would this be the same problem? the L/R band?

[pishta]

Ok, Done! the low/reverse strut fell out when I removed the pan. It was never seated properly. What a bitch to get back in! I had to drop the valve body which was no big deal, except the selector and kickdown levers must come off and That meant I had to drop the driver side exhaust, etc.... Anyway it is back in and now Im looking up the band adjustment by turning the drive shaft method. Thanks guys!

[fox]

Don't adjust the bands by the driveshaft method!
Set it for 1/4 to 5/16 clearance between the pin and lever.

[pishta]

pin and lever? I dont follow. If I have 1/4 inches between the adjuster and the strut, im way farther than 2 turns out. Also the rear drum doesnt turn in the driveshaft drag method. How do you adjust that one? Im getting an inch/lb torque wrench tomorrow to do it by the book.