Re: Writeup: DIY transmission fluid change
(sigh) I'm a bit reluctant to post this as I feel like a complete idiot but maybe someone will learn from my (many) mistakes.
1. Do not attempt to drop the pan of the transmission if you do not have a torque wrench that measures in inch/pounds (read that again: inch/pounds) and specifically has a labeled setting for 70 inch/pounds. Do not assume that you can extrapolate down on a torque wrench whose lowest setting is 25 foot/pounds. Stupid me, I tried to do just that. I now have one sheared off bolt on my transmission pan (but no leaking so far). Extrapolating down likely missed by 5 to 10 foot/pounds. Also, at such a low setting the "click" sound made by the wrench is so subtle I simply didn't hear it. At higher foot/pound settings the click is very obvious. With the stereo on in my garage I completely missed the click sound. 70 inch/pounds = 5.8 foot/pounds. That isn't much.
2. The correct hose to drain the fluid from comes from the passenger side of the radiator. If you have fluid coming out of the metal pipe (that comes from the transmission) then you have disconnected the wrong hose. I got to looking at the routing of the hoses going into the radiator and made a bad judgement call. It seemed to me that the hot fluid would be going into the top of the radator and cool fluid would come out the bottom (heat rises, right?). I guess I didn't follow the routing of the hoses correctly or my judgement is just plain wrong. I wasted an estimated 3 quarts of (most likely) brand new fluid because I picked the wrong hose.
3. Keep very careful track of how much comes out and how much goes in. I thought I was doing a good job of this but my screwup in #2 (above) threw off my tracking plus I think my teenage assistant who was in charge of putting hash marks down (and stopping/starting the engine) wasn't as accurate as I wish he had been. I was covered in transmission fluid and didn't want to get my pen dirty. Next time I'll use a disposable pen that will get dirty.
4. Make sure you have plenty of fluid. I started with 15 quarts. I thought I was all done with the flush and had three quarts left over. So I used two of those quarts in the transfer case (which was way more nasty than the transmission). Before doing the transfer case I checked the fluid level in the transmission multiple times. I had it warm, changed gears more than once and checked the level more that once. But what I didn't do was drive it around. When I went to do that (after the transfer case was done) it was obvious that I was low on fluid. I put the one remaining quart in and the transmission was still slipping so I'm pretty sure it's still at least a quart low. Maybe I misread the dipstick. Maybe the fluid was splashing up on to the dipstick and that threw off my reading. I don't know. The service manual says that the dipstick cap is to be inserted 180 degrees from the normal, bolted position. I didn't do that so that could also be the problem but I think it really comes down to not keeping good track of how much came out. (I did use a gallon bottle marked off in 1 qt gradiations)
5. A hot transmission gets the job done faster. I drove mine around for a good hour before I started but before doing the transmission I took care of both differentials, the engine and one rear shock absorber. The OP noted that he could not pour in new fluid fast enough to keep up with what was being drained. I had the opposite problem. I did a lot of waiting on the old fluid.
6. Buy the fluid in quart bottles. I bought one 2.5 gallon jug and then five quart bottles. Single quart bottles are easier to handle than a 2.5 gallon jug.
Not everything went wrong. The fluid did need to be changed. I had not planned to drop the pan even though I had all the necessary supplies (gasket, lint free towels, brake cleaner, etc). After draining the fluid from the pan using the drain plug I changed my mind. The fluid looked like a batch of finely pureed strawberries (for strawberry shortcake) that had been in the fridge past its Use By date. I did grab a sample that I'll send to Blackstone Labs. It wasn't horrible but I think it was well used due to off-roading and towing.
I used a plastic putty knife to get the pan to detach from the transmission. So I didn't take any gouges out of the pan or transmission.
I put clear tubing on the metal pipe and routed it into the same bottle that the black hose went into. Yes, some fluid will drip from the metal pipe. No, the transmission will not suck up fluid from the bottle. That would just be way too convenient.
Getting the rubber hoses disconnected from the metal pipes was very difficult and time consuming. I ended up gently wedging a small flat blade screw driver between the metal pipe and the rubber hose and gently prying them apart.
You probably could do the under-engine work with the skid plate in place but it's a lot easier with it removed. Plus, you don't have to clean the skid plate. As it is it looked like someone bled all over the place under my truck. Gads, what a mess. Conversely, the top of the engine is spotless. I didn't spill anything up top. I used a clear hose that fit INSIDE the dip stick tube and then a funnel that fit inside the clear hose. I used a bungy cord to hold the funnel upright when I wasn't using it. This kept the funnel from dripping on the engine and also kept it out of the way.
Keep lots of disposable gloves on hand. I think I went through 20 pair to do all the work. These are the Black Gold ones from JC Whitney. Maybe not the highest quality but I had hundreds of them.
I replaced both of the spring clamps on the rubber hoses with clamps you can screw tight. I don't know if those are the clamps people are saying go bad. But I replaced them anyhow.
Will I ever do this again? You bet. Now that I know what NOT to do I should be OK. Will I ever do this solo on someone else's Titan? No way.
Update: I added 2 quarts and everything is just fine. I'm not sure what I'm going to do about the bolt I torqued off. My neighbor is a retired machinist. I'm hoping he knows some tricks to take care of it.
«Granite '07 LE Crew Cab, 4x4, Big Tow, Off-Road, Side Curtain Airbags, Sunroof»
«ClearBra, Leer 100XQ, MM SI9500 Winch, 18" Magnaflow, Berk b-pipes, Volant PowerCore, AMSoil bumper to bumper, Uprev tuned, CSF radiator, e-fans, JBA LT headers»
«SAW Coilovers and rear shocks, PRG upper control arms and shackles, Hellwig rear sway bar»
Jim aka Bionic Whore™
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Last edited by HRTKD; 06-19-2011 at 09:14 AM.
Reason: post-disaster update