Hi all, sorry i havent been around much lately, been putting all my efforts in restoring an old bass boat...

anyway, one of my worst fears - transmission trouble in my truck, is coming around. About a week ago i started having trouble during gearshifts while the truck was in overdrive. now, overdrive wont even engage at all, it just revs freely and if i give it enough gas, it will eventually downshift violently into 3rd. if i turn overdrive off, it seems to shift and drive normally.

i dropped the truck off at the dealer, but of course its not going to be covered under warranty, truck is heavily modded and at 38K miles...

im hoping that it will be a cheap fix, but im not counting on it. if they tell me its going to cost say $1500+ to fix, im seriously considering buying a monster box from Jasper or Factory Tech. I dont have the know how to repair a transmission, but im fairly confident we could drop in a replacement... anybody have a monster box for these new 4R75E's?

Im also trying to figure why this happened. The gears that are run hard: 1st, 2nd & 3rd, have no problems. the only thing i can figure is the cause would be my larger wheels/3.55 rearend ratio. on the highway, it would constantly be downshifting into 3rd, even under extremely light throttle pressure. im guessing all this extra shifting wore out some of the clutches or valve body or etc.

im considering breaking down and regearing my rear end to 4.10's to avoid this and get a little more off the line ummmph

so anyway, im wondering if anyone has had trouble like this, and if anyone had opinions of the replcement monster box tranny. thanks

 

Isn't that covered under powertrain warranty?

 

I don't have any information on the transmission but I do have 33" tires with the 3.55 R&P and my truck will hold OD just fine while crusing on the freeway. Almost sounds like there was something wrong with the trans from the beginning and it just decided to let go 2k miles after the warranty. What little research I did do on the monster box I couln't find any 4R75Es so I don't know if they have them and are just not listed on the site or what the deal is.
Here is what they have listed for gas applications.
Transmission

 

I was told a while back that cruizing in 4th gear (highway speed) and gunning it was hard on the trans.... also holding the gas pedal WOT and shifting into 4th at WOT was bad too.

Monster Box should bolt right up to the engine... but as fas as trans support or what not.. I don't know.

4.10's would certainly help.

 

Sounds like the tranny was doomed to begin with like someone said above. I'd call a ford rep and see if they can help you out some. On my last truck i was having major 4wd issues and the guy (from chevorlet) told me that if my transfer case went out at 38k miles that he would get on the phone with a rep and they would help out some on the cost. I traded it in at 18k miles for my ford.

 

Regearing would put much less stress on your tranny, and more on your rear end. Which I believe can hold up to a little more abuse, and a much smaller pricetag in the end if it does break =]

 

I had a similar problem. Basically transmission wouldnt shift into the next gear and only stay at 30mph, after 30mph it would just rev like crazy. Took it to ford dealership and they fixed it no prob. My truck was modded, just look at my sig. Dealership found burnt disks or something to that nature and replaced it under warrenty. On the invoice they gave me the damages totalled 2101.87 cents that I didnt have to pay. I asked if this happened alot with this truck and he said every once in a while he would get one. Good luck buddy. Now looking to get 4.56 gears just in case.

 

Yeah, but he's got supercharger bolted to his engine, and hes at 38K so warranty is out of the question. Dude, when this this start happening?? What were the first signs of it? Me and you have a very similar setup so I need to know what to look out for. I got 41K on mine so far and it has been almost flawless cept for that one injector that stuck a while back.

 

i did have the occasional violent "clunking" downshift into 2nd ever since i put the supercharger on; but since i knew nothing was going to be covered under warranty, and it didnt happen very often, i let it go hoping for the best.

in the last week or two, i have noticed a slight rubbing type feel when i take off after first starting the truck. it was minor and almost felt like a torque converter problem, which may have something to do with it. ill have to see what the dealer says after they do their "diagnostics". tomorrow morning, they will have had the truck for 2 days without calling me yet. im going to call them and find out what is going on.

as far as the monster box, i did see that the factory tech web site doesnt offer one for the 4r75. but here:

http://www.jasperengines.com/monster-box.htm

they do have a replacement for the 4r75 but its hard to see if its the monster box or just a basic remanufactured tranny. i might call them up after i talk to the dealer. if the dealers prices are $2000 or under and provide a decent warranty, i might let them fix it. but if that ~$2000 jasper tranny is in fact a monster box, i might just get one. ill find out tomorrow...

i would actually love to figure a way to drop in a different tranny. a 5 or 6 speed would be nice. manual or auto, anything is better than a 4 speed...
if it wouldnt be such a nightmare, i would actually consider it, but o well

 

Hey anything is possible man.......well with money and time and fabrication that is... As far as the harsh 2nd downshift.......that's Roush programming for you. Anytime I would snap the throttle down and I was in overdrive, it would SLAM into second very hard. Since the tuning it doesn't do this anymore, but slips into 2nd smoothly and then applys power. I wonder if that bad progamming is what messed up the trans in the first place..........

 

wouldnt surprise me one bit... i used to think that altering the roush tune would lead to problems, but i had a feeling as soon as i felt how it shifted, taht i would be having tranny problems down the road. i mean i cant complain. i have 28,000 HARD miles on the truck since the supercharger install, and its amazing how well its taken a beating so far

and money is the main issue right now. i wasnt really planning on spending much money on my truck for a while. i am finishing up this boat and hopefully start saving for a new house. but it looks now like im going to have to dump some money in. after the tranny issue is resolved, i might have to bite the bullet and fork out for new gears and a custom tune. on the bright side, the truck should haul even more *** when its all said and done

 

I'd love to get a MonsterBox, they are amazing!!

 

That sucks man, sorry to hear. I'm worried about that day as well. Hopefully your fix is quick and cheap, but if you do go an aftermarket tranny route, keep us informed. I searched for the monster box for our trucks and couldn't find it either. Hopefully there is something out there better than stock that will be a direct replacement.

Good luck!

 

4rw70 and 75 are almost identical... from what I read. Don't take my word on it, but only differences should be in the internal working of the trans. Post it up in the trans forum and you will get a finite anwser.

 

i called up jasper engines and transmissions today, and they confirmed that they dont have a monster box out yet for the 4r75e. the 4r70 and 4r75 are very close, but i have no idea how difficult it would be to adapt a monsterbox 4r70 to fit. i dont have the confidence to take on a project like that or do i have the funds to pay someone else to figure it out

i talked to the dealer today and they said that it was an internal tranny problem and would probably cost $1500-$1700 to fix depending on what they found. since they will provide a 1 year warranty on their work, im going to let them do it. ill post back when then tell me what they found...