Thread: Developing hard-shifts / Towing / Need Opinions

Originally Posted by Scottydoggs

if you wanted to do a shift kit, the time was when the pan was off. you may want to suck out a quart of fluid, and dump a quart of lucas trans medix in there, it will help keep it alive longer.

get a long clear plastic hose, that fits down the dip stick tube and to the ground. push it down the dip stick tube till it dont move down any more, then siphon into a empty quart bottle on the ground.

I wanted to get new fluid in asap and the shop went straight to "full rebuild" when I mentioned a shift kit. I would be open to putting in a shift kit at any time. But for $100 I couldn't have bought everything I needed to drop the pan (needed a in-lb torque wrench in addition to all supplies). I will consider the lucas.

Originally Posted by 02NavyBlue

As long as the material in the pan was just dark sludgy stuff, and there wasn't a mound of it, that's normal. If there were silver metal flakes or something, I'd be worried. The slightly harder shifts probably happen when the trans is getting to a high temp (210+), and our impala does the same. If I were you, I'd throw in a shift kit and trans cooler. The cooler is something that should have been installed before towing things around that weight for long periods of time, but still doesn't seem too late. Which trans cooler did you order?

I verified that it was mostly clutch material and he said there was a normal amount of brass(?). I notice the (ever so slight) firm shift at low speed and low throttle. I may even be making them up as this transmission probably isn't the smoothest even when I bought it. There's still a little push to the shifts (right?). I bought a hayden kit from rockauto - the the Hayden 403. I hope that's a good choice for me.

Originally Posted by matt5112

I beat the living crap out of mine for 15K after it had a 75K on it. The only real issue was an overly long 1-2 shift at WOT only. Other than that, it was very well behaved. Unfortunately, it's not a very long sample.

On the second vehicle with a 4t65e, dropped the pan 6000 miles ago, installed the transgo shift kit and filled with dex VI. It did shift quite a bit quicker. However there was a very dark coating of dark clutch material on the pan and the bottom of the transmission. Just this week I dropped the pan again to change the filter and fluid because the vehicle has 78K miles on it with zero maintenance records after 20K miles. This means the fresh fluid will do a very good job of clogging up the filter right quick. I also opted for a bottle of Lucas transfix, a cooler and Dex III. Despite all of this, the transmission shifts exactly as it does before. Which to be honest is a rather good sign, means nothing in there was going wrong that the Lucas could help out with. This time there was a very light coating on the pan and case compared to the first pan drop. Again, very short sample, but still no real issues.

If the hardest you are on the vehicle is towing, and even then, you're not trying to drive it hard, it should last for a while yet. If it does go, a back to basix build from TEP would last longer than your existing transmission has and is under $1500 to your door. Just pay a shop 400-500 for the install and you're back up and running for another 100-150K easily. The only other question is are you willing to keep your care for your car for another 100K miles. If so, it's a relatively small investment compared to getting into another used car, certified or not.

The reality of this transmission is, it will run for 200K miles and more. But there are other small issues that can develop, and take it out prematurely. There's really no way to predict if something like that will happen. Since your car has the newest valvebody style, it's least prone some of the major issues. But for example, you still have the GM short lip input seal which can cause the car to not move from a stop very suddenly and without warning. The forward band can crack and fail, leaving you only with the 1-2 manual band for forward movement.

It's very tough to say exactly how long in any state, but a properly built replacement will do a better job for longer than a factory replacement. On the flip side, a poorly built replacement might give up after a couple days. There are many horror stories out there about poorly rebuilt transmissions.

I'm hoping my trans feels exactly the same or better than before (even though I think it can only get worse when you add new fluid). I've done a fair amount of towing in hilly western WI at 60-70mph with too much shifting between 3 and 4. I am going to stick it in 3 from now on - screw the mpg's. If I could dump it for $8k+ and buy another vehicle that would certainly be an option; I paid $13k for it certified with 28,000 miles. I would be sad to see it go for sure.

The shop ballparked $2800 for a rebuild. Would that be any more or less certain than a TEP rebuild? What do you mean a proper rebuild may work better than a factory replacement - whats the diff?

Thanks to all contributors!

Originally Posted by stocker

I wanted to get new fluid in asap and the shop went straight to "full rebuild" when I mentioned a shift kit. I would be open to putting in a shift kit at any time. But for $100 I couldn't have bought everything I needed to drop the pan (needed a in-lb torque wrench in addition to all supplies). I will consider the lucas.

I refuse to torque bolts with such a low torque spec that are simply holding the pan on. Namely because I don't trust my in-lbs torque wrench. I simply thread by hand, then snug with the ratchet.

I verified that it was mostly clutch material and he said there was a normal amount of brass(?). I notice the (ever so slight) firm shift at low speed and low throttle. I may even be making them up as this transmission probably isn't the smoothest even when I bought it. There's still a little push to the shifts (right?). I bought a hayden kit from rockauto - the the Hayden 403. I hope that's a good choice for me.

Brass wouldn't be normal at all. I'm not a fan of smooth shifts as it simply means the clutches are slipping more. Quick firm shifts are what I prefer. However you normally don't get that unless there is a shift kit/bumped line pressure in the tune or the transmission has been built to do that.

I'm hoping my trans feels exactly the same or better than before (even though I think it can only get worse when you add new fluid). I've done a fair amount of towing in hilly western WI at 60-70mph with too much shifting between 3 and 4. I am going to stick it in 3 from now on - screw the mpg's. If I could dump it for $8k+ and buy another vehicle that would certainly be an option; I paid $13k for it certified with 28,000 miles. I would be sad to see it go for sure.

The point wasn't the new fluid so much as the Lucas transfix. Keeping it in one gear might be fine. Your fourth gear hub won't strip, so that's a non-issue. GM fixed that a while ago. As for the current value, it truly depends what they sell for in your area.

The shop ballparked $2800 for a rebuild. Would that be any more or less certain than a TEP rebuild? What do you mean a proper rebuild may work better than a factory replacement - whats the diff?

Thanks to all contributors!

That would be $800 more than a TEP rebuild of his "back to basix' nature assuming $500 for install. Link here: New-Back to Basix

Originally Posted by 02NavyBlue

Hm brass isn't magnetic, so it wouldn't be on the magnet. These transmissions aren't meant to shift so that you can't feel them, but you also shouldn't have your head get jolted back by them either. Mine shifts pretty firm when it's cold, you can feel it pretty good but smooths out when it's warmed up. All normal. There should be just a little bit of push to the shifts.

The hayden 403 is a good size for the N/A 3800 with normal driving. The 404 probably would have been best for you, but what you bought will be much better independent than the stock setup.

I'm planning to run inline with the radiator. I only want to improve on the stock system cooling but not eliminate the ability of the radiator to warm the fluid at -20 in MN winter


MATT5112: My goal for maintaining 3rd gear is to simply to eliminate constant shifting between 3rd and 4th under towing loads at transmission temps of 215-228*. I'm guessing that made most of the clutch material.


Overall, my trans would probably feel fine to anyone. I think I'm trying to compare to the dealer test drive 3 years ago... not easy.