So I only have 105K on my truck and the transmission works fine. I have an e99 truck so I plan on replacing the radiator with the OTW cooler in it and add the 6.0 cooler. I pull a heavy 16k to 17k trailer once or twice a month a few hundred miles so that is why I am concerned about the transmission. I plan on putting in a John Woods transmission when the time comes. I have the money for it but if I don't need to replace it yet, I might as well hold on to my money for a while. The truck is stock except for the exhaust and the AIS intake that is on the way. I probably wont add a chip until after I swap the tranny for the JW unit so I will be staying at stock output levels for now.

Is there normally a sign that the tranny is about to give up or will it just go out one day? Should I just bite the bullet and put the JW unit in now since I pull heavy or will it hold up to stock output levels?

Thanks for the advice.
Chris

 

Its a crap shoot really. It could go out tomorrow with no hints (like mine did) or it will last another 100k. And by then you may want to upgrade the truck to something newer and you can put the money towards that instead....just thinking out loud.
I got 241k out of my original trans w/stock cooler, no OTW radiator. and it pulled a camper it's whole life.
Personally I would just toss in a JW valve body and add the OTW (oil to water) radiator and drive it.
When the trans in my e99 F250 started to go out it started slipping in 4th. I must have driven it another year like that. Just kept it in third while towing locally.

 

Probably cursing myself now, but still on the original trans in mine, 270k on it. Keep contemplating just heading to BTS just as a proactive measure...Most of the time I would be fine, the time I would hate for it to go out, would be to or from RRE each year, that's what's always in the back of my mind.

 

I feel ya, I had to miss RRE last year to afford my BTS Trans....
On the bright side, I have no excuse to miss RRE this year.

 

My e99 trans lasted 133k. But if your pulling 17K I would get and extra cooler or 6.0l and do the radiator mod. You mit want to go the cheap root and get the 6.0L cooler when its time for the trans. JW can put it in along with DP tuner. Thats how I did mine.

Chet

 

I'd defintly vote for a JW or BTS VB at the very least, you'd be suprised even without tunes how firmer and crisp the shifts are, faster quicker shifts means less heat and I'd say less stress. I got a 180,000 on my stock trans with a JW VB, with the thru the stock rad cooler with a Derale inline to the stock cooler(thanks Clay) and not towing in the heat of summer last year and never got over 150*-160*. Add a VB and inline cooler and change your fluid at 30,000 and roll with it..

 

Honestly, I wouldn't replace it until its necessary. If you want to do the VB, that would be a good upgrade and could be all you need for the life of the truck. When mine went, it started slipping between 2nd and 3rd gear, and I could hardly get the truck up to speed when towing my 5er. I tend to go with "if it ain't broken, don't fix it" mentality.

 

Thank you everyone for the input. Reading everything online makes you think that the tranny is totally junk and it could blow at an moment.
I started 2nd guessing replacing it now since I am not having any issues with it.

The first 100K of the truck never saw any towing of any weight so it has had an easy life so far. It has only started pulling my heavy trailer recently. I will be buying the new radiator and 6.0 cooler tomorrow. The VB sounds like a good idea so I will do it with the fluid change at the same time.

I don't put many miles on it so this might just last me several years without problems if I take care of the heat and shifting issues now. My only real concern was I pull my trailer to the races out in the desert so I would hate for it to go out on one of the two lane roads out in the middle of nowhere. It sounds like most failures have some indication ahead of time though.

Thanks again and all comments are appreciated.

 

You might consider sending fluid samples to a lab for analysis from time to time. That can sometimes provide a fair amount of notice when things are going bad inside the case. I sample my trans fluid every 15-16k or so. Right now I am on a 45k fluid change cycle (complete transfusion of fluid every 45k with samples every 15-16k...)

These transmissions can last a while if maintained properly and not abused. We've owned 18 of these trucks here at work. Our policy is to change trans fluid once a year no matter how many miles are on the truck (all are PTO units..). As best as I can tell from our service records, the only transmission failures we've had are the 2001 models, I presume the failures may have been due to the mechanical diode issue...or it just could be a weird coincidence. We'll never really know because we don't track the repairs with that much detail.

Here is an example of a trans fluid lab report from my personal truck(see attached). This unit does not have the oil to water cooler but does have a supplemental TruCool HD cooler. No external filtration, Motorcraft Mercon V fluid. Unit was rebuilt 152k miles before this sample was taken. Rebuild kit was Transgo Tugger overhaul kit with PTO clutch and TC upgrade.

It's kinda hard to evaluate for certain...but it seems like using a lab for fluid analysis has been beneficial. The lab we use provides all our information via an online website that we can access via user name and password. So, we can sort the information hundreds of different ways. Last week, we decided we were going to swap one of our trucks in Arizona with another one in Fresno CA. Prior to departing, we logged onto the website and checked the last trans sample for the Fresno truck and saw the acid number was a little higher than we expected. We then sorted the information to show us a comparison of all samples fleet wide for all 4R100 units just to verify that it was time to change that fluid. We instructed our local branch manager to have that truck dropped off and get the fluid changed before we drove it all the way back to Arizona. That truck arrived today without any issues (except for a very tired driver...).

Did we save a breakdown? Probably not...however we did make a decision to spend some money on maintenance based on what we consider to be valuable information. In your case, if your trans is working well, then there is no reason to change it. Just keep doing your maintenance and possibly send in for lab reports on a regular schedule. That seems like the best recipe for minimizing untimely breakdowns. Just my $.02....

Oh yeah...a 6.0 cooler is a nice upgrade.

 

Mine just went one day, lost OD then start slipping in 3rd, then second. This all happened in a 5 hr span and I wasn't towing anything.

You could be fine today and gone tomorrow but I wouldn't do anything more then the VB until it craps out.

 

I know how you feel. my trans was ok, only 87,xxx mi. but to many times the temps would get up to 230+* with no trailer. I go up a switch back road to my cabin, takes about 20 min. At the time i didn't know about 6.0 coolers and all the stuff you could do to make it better. then i learned about the things that can fail on a 4r100. its a great design, been around a long time as the e4od. it just has parts and simple things that should have been done better. the hd4r100 is more like it should have been to begin with. so i mulled it over for months, even called J.W and talked to him. finally decided that i don't want my trans to go while i'm at my place where i can't even get a cell signal. it was for peace of mind. i got my truck new and have no plans on replacing it, so it was spend it now, or spend it later. I'm glad i got it. It pulls so nice.

 

The 6.0 trans cooler will really help it when pulling. You might also consider getting a temp gauge put on it. With the amount of pulling that you say your looking at..... save your money in the bank for now. If you were pulling hard and heavy every day, that is when I 'might' consider replacement or overhaul with a JW or BTS. I abused my tranny (for years) by the way I was pulling my camper and the OD blew out at 107,000. At least you are thinking ahead to get the best out of your tranny.

 

Thanks again everyone. I do have gauges on the truck, it was the first thing I did. It normally runs no more than around 170 to 180 max when not towing and normally cooler than that. Towing on longer gradual grades, it will get up to 210 to 215. It only got to 225 once for a short time when I was running around 10 to 15mph on a dirt road for about 10 miles. When I saw it was climbing up to 225 I put it in 4 low and the temps came back down.

It has 105K on it and it was serviced once but I am not sure at what mileage. I will take a fluid sample and send it in before I put in the radiator and cooler along with replacing the fluid with Mark's method that was posted.

I am going to go with the JW valve body since he is the one that I am going to have rebuild it once it is time.

I feel a little better now about waiting to get it rebuilt since some of you have got a good amount of mileage out of yours before needing it. I know it is still a crap shoot but hopefully doing the mods now will put the odds a bit more in my favor.

 

When you do decide Clay at RiffRaff diesel here sells them and for a great price. When your ready to do the job don't get discouraged, its really a simple bolt on install. I did mine in less that a hour and a half start to finish with fluid refill, great mod. Here's what you'll be replacing, the acumilator VB I believe its called. And this is where it goes, just remove the trans pan

 

I do plan on buying it from Riffraff. I just need to figure out which weekend I am going to do it since I will only have 3 weeks to ship the core back to him. It will be a VB, 6.0 cooler and radiator swap weekend. Sounds like fun!