I remember when I was first getting into diesel trucks and I was on the hunt for my first truck. I knew I wanted a six-speed transmission, but not because I wanted to row gears. I was terrified of the shop bill for when an automatic transmission in a monster, diesel truck transmission would go out. At the time, 17-18 years old, there was no way I was going to be able to afford that so manual it was.

Fast forward to a few automatic trucks later, here is our own Project TowBoat. You’re familiar with this truck because we have covered this truck in upgrades and repairs over the last few years and the truck has been absolutely perfect. We set out to create this template for the perfect tow rig. If you wanted a tow rig that performed spot on, no issues, great reliability, you could mimic this build sheet and get that.

Guys, gals, no matter what you do, there will come a time when your baby is down. You just have to tell them it will all be okay soon. For Project TowBoat’s transmission, it’s had a good run. The truck has 110,000-miles now and it’s finally throwing in the towel.

Well, the truth is is that everything has a shelf life and after years of abuse prior to my ownership and then more abuse when I became the owner, things will and have inevitably failed. For years, everything was fine. It was nothing to load the race truck up on the trailer and just head for Florida to race. 600 miles and never skip a beat. Well, over the winter when pulling a moving trailer, I encountered my first issue.

The truck would not come out of fourth gear. Once I reached enough MPH for it to engage fourth gear, it wouldn’t come out. Not thinking, I stopped and tried to manually set it in first gear and row the gears manually. Well, it wouldn’t come out of fourth and naturally I was on the steepest hill in southeast Missouri. I’m sure the clutches on this transmission are on fire at this point because I made it make it up the hill.

I made a call to Paul Cato over at Maverick Diesel that evening hoping he could give me some advice on this because it was my first 68RFE and I still had 40 or 50 miles to go before I was home. “It sounds like the overdrives are hating life,” Cato said. “I would just clear the codes out that popped up and get it out of limp mode and try and get it home.”

Part of me wonders how this transmission really lasted as long as it did. Compound turbos, custom tuning, my foot, and usually a lot of weight behind it, I’m impressed.

Sure enough, whipped it into a gas station just off the highway, cleared the codes, and we were on our way. The trans was high revving, slipping, downshifting, upshifting, basically doing whatever it wanted during my attempt at getting to 70-MPH. Luckily for me, I made it home. Thankfully this was in the offseason and the big loaded trailer wasn’t behind me.

Fast forward to now, it has been a few months since this oopsie. I have managed to make this slipping transmission last a few hundred more miles. In fact, I’ve drove it so much that I know at what temperature is too much. If it reaches 160-degree transmission temperature, you’re not going to have 5th or 6th gear. Is this smart? Probably not. Is it working? Yes.

What Now?

With me not having a replacement transmission here and no shop time scheduled for this one to be repaired, my only option was to just run the truck as long as I could. I happened to have some product on my shelf that I thought could help from Hot Shot’s Secret called “Shift Restore”. I’ve had such good luck with their other products, why not, right? It’s already toasted, why not see if it helps.

I understand that this product is really for transmissions that aren’t destroyed they are just in the early stages of wear and tear. I think the bottle called for 3/4’s of the bottle given the capacity but I went ahead and used the rest of the bottle. I wasn’t planning on using this stuff because I planned on everything lasting forever. Ha.

One last very slow ride over the weekend to the race track. The transmission got hot enough that it wouldn’t engage overdrive which meant we were only allowed to do 50-MPH on the interstate at 2,500 RPM. Not smart, I know. All in the name of racing, though..

I was pleasantly surprised that I could literally tell a difference. It took probably 20-30 miles to get mixed in there I guess, but it really improved the trucks driving. The slipping didn’t happen anymore, the temperature was actually lower than before, but there was no change in sound which was a bullet point on the bottle.

As the days went by, it just slowly went back to its old way with the slipping and getting hot. With good reason, too. So, something to take away here is that if you have a transmission starting to have issues, check this stuff out. I know I will. Here we are now and the truck damn near doesn’t move but help is here. Stay tuned right here on Diesel Army to find out what we’re doing next. Project TowBoat is coming back better than ever very soon.