just lost reverse in my plow truck

[sloppy2nds000]

backed off the pile of snow about 2 feet and then caput. no noise, no slip, just stopped reversing. still runs drive just fine, all 3 gears. no slipping. i just rebuilt the main body of the tranny. but didnt take the overdrive unit off cause my kit didnt come with od stuff in it as far as i could tell.

i watched the video on rebuilding the od housing to figure out what all the extra parts were for and didnt see a place for them in the od unit. it seems they were for other trannys of the same species. what was left were accumulator piston rings and some o-rings.

[dazedandconfused]

Low/reverse band come loose? That's all I can think of right now. I've been in a plow truck for the last 12 hours myself.

[cmann250]

The strut or anchor likely came apart. Simple fix. Hope you welded a drain plug in the pan the last time you had it off.

[PToombs]

Bent the strut, I bet.

[sloppy2nds000]

broke the reverse servo. i know its a floppy little hot dog in a hallway. but what causes it to bind and break? the new seal i put on it made it pretty darn tight in the bore. fortunately it didnt hurt the bore.

i did weld a drain plug in it last weekend, glad i did. save me 2 gallons of fluid. only had to toss a couple quarts. i strained and filtered the fluid before i put it back in.

just out of curiosity, how much play should the sun gear have where it mates to the drum. seems to have more play than the one in the trans i borrowed the servo from.

i plan to order billet servos and accumulator monday or tuesday.

[sloppy2nds000]

the damn thing is trying to shift into reverse when it should be shifting into either second or third. i cant tell which it is because of how sticky it is. what causes this. there was some fresh clutch material chunks in the pan if they were to get cought up in the band they could cause it to grip and stall the sun gear couldnt they. the chunks were from the black bands not the light cream colored ones. so thats the rear pack if i remember correctly.

[sloppy2nds000]

so i came in the house to after plowing a couple driveways in my neighbor hood to post that last post. went back out to the truck to leave to plow, and no reverse. it broke the servo again if i had to guess. so that means that the band wasnt grabbing, the servo was being pressurized right? so im back to removing the whole tranny now i guess and checking for why there was fiber debris and cracking the valve body open to check for debris and probably getting a new clutch pack. guess ill have to bore check and mic the servo bore too at this point.

[cmann250]

Refresh my memory. Is the rear servo plastic?

By any rate I think you're using used servos that are worn and therefore easy to get cocked in the bore. I could see some debris getting caught under the band and causing the servo to break.

I understand that this truck is important to your business, but if something inside the trans lets go and you don't tear it down to at least clean it good, you're wasting your time.

[sloppy2nds000]

the servos are aluminum, the accumulator is plastic. the servos might be worn slightyly and getting cocked in the bore, especially the rear. it has no guide to ride on unlike the front servo. but the issue is whats causing the servo to pressurize and and actuate the band strut when its trying to shift into i want to say 3rd gear. but like i said it was dragging so hard that i couldnt tell what gear it was trying to shift into. the gears were fighting each other. i want to say i was probably going about 20mph. but my speedo is way innacurate even with a new speed sensor.
i just replaced all the clutches, bands and seals last sunday. theres probably 150 miles on the trans after the rebuild all was well then it just goofed up and quit. i plowed tuesday and thursday without any issues, it was working flawlessly both days.

[ellis93]

How's the adjustment on the rear band.....how much movement does the piston,lever have before band apply?

[DodgeFreak]

I think there's more problems than the rearband. If you're getting clutch material there's clearance problems someplace or something....What all did you do again?? How much pressure are you running??

[draginmopars]

have you checked the end play of the input shaft
.010 to .025

Planetary End play ( .010-.044" )

It may have ate a fiber thrust washer.

[sloppy2nds000]

new rear band 72"#, then 2 turns out. new front band 72"# and 2.5 turns out. allen screw stock setting. tranny rebuilt last weekend with a raybestos kit. but i didnt do much to the valve body as it was working flawlessly,and the kit didnt have much for it. i rebuilt the tranny because the tc crapped out on me, and i figured while im in here i might as well replace some stuff. it took me 34 hrs over 2 days to do the job. rebuilding was probable 2 hrs and installing the trans was 30 min, installing the transfer case was over an hr, the reset of the time was fighting the truck apart and back together. it was miserable. im not looking fwd to doing it again. so anyway, the friction material debris was black, and either came from the second clutch pack or the rear band. its thin strips of material. the front clutch pack was tan colored material and the front band was was also a lighter color. the truck is stock, the tranny is stock (for now), just gotta get thru the plow season and build it right this summer.

like i said before, i plowed all day tuesday and thursday without a worry in the world. truck ran like it did 6 years ago. i was happy. my customers even noted that i looked to be enjoying myself.

now that the servo is broke again, the truck shifts super smooth like it should, it holds solid in all gears, and was pushing snow in my barn yard in second gear without any qualms. all left turns you know, with slight counter turns to the right. set that rear and keep em spinning. dont let out. ha! ok thats enough of that.

its like the one guy said, theres a bigger problem here than line pressure or a sticking band. i was planning to buy a valve body kit today, but was hoping to pick your brains first before i throw money at it, and it doesnt solve my problem. i need to install a shift kit and what not but im getting short on disposable cash so i need to spend it wisely for the moment.

i do feel that the sun gear had a little too much end play but was probably not out of spec. but it was riding perfectly in its same grooves where it mates the front drum. the front drum seemed fit as a fiddle. the whole tranny was in overall great great shape and probably didnt need me inside it, but i had the parts so i swapped them out, and they were cheap enough at 200 bucks for the kit and bands. the old reverse/low band was pretty worn but still serviceable. it was the only part that could have used replacing and it got it.

[ellis93]

I say it's something simple.....and you are over thinking it. This trans is one of the most simplistic you can try to build but have some funny little quirks.

I just asked about the adjustment of the rear band to know just how you did it.

Your problem will more than likely be a cross bleed somewhere,or you bent the finger on the manual lever where it indexes the manual valve. If that thing gets out of adjustment it'll cause all kinds of hell.
Did you take any of that apart or have issues in that general area?

[sloppy2nds000]

ellis, i didnt mess with that stuff when doing the rebuild, figured id leave well enough alone if you know what i mean. i know these trannys are simple, theyre kinda sweet like that.

it looks to be a cross bleed issue. and it totally trashed my new reverse/low band, so i yanked her back out. came out a little quicker this time as i anti-seized every thing, and now theres no chassis saver caked to the nuts and bolts. but still took the better part of the day.

by the way chassis saver sucks, use por15. i stripped, degreased, wire wheeled, chisseled, and scraped the old scale; then washed the frame. GARBAGE. all that work for nothing 2 years ago.

so i ordered all new billet sonnax servos and accumulator, fairbanks shift kit, and neutral insulator from a place called transtar. holy cow it was like 80 bucks cheaper than PATC, which was the cheapest place i could find for parts. this place has everything you could possibly want. but you have to kinda know what youre looking for, or even have the manufacturers part numbers, and you have to call them and talk to a sales person. i talked to pete, he was great.
the reason i chose transtar was because theyre outta michigan and can get me my parts today/next day for ground shipping prices. and im glad i did. parts were so much cheaper that i was able to buy the intermediate servo and it only cost me 45 bucks.

accumulator 20, power wedge 19, rev/low servo 29, int/2nd servo 45, neut/rev insulator 11, fairbanks shift kit 53. so $175.00 for parts = happy nick