Transmission Maintenance

[03_LT_EXT_4X4]

I decided to bite the bullet and *finally* make my first post after really only finding some conflicting posts and beliefs. A little bit of history: the original tranny died at roughly 50,000 miles (ten years ago or so) and the current one has never been serviced in about 60,000 miles since being installed. The TB has been my parents' since brand new and within the last couple years I've slowly been gaining their trust to work on the cars instead of the random mechanics in town who have practically never completed a job right the first time.

So after much research, and deciding I have no idea where to start (or finish), I figured it'd be best to ask the question myself. Where the heck should I start (and finish)? I like to think myself a pretty capable *mechanic*, but in reality I'm nothing all that special. I can follow a guide or video fairly accurately, but I'm definitely not capable of too much. The 1-2 shift is pretty firm and sudden to the point where I would imagine there could be a TCC or other valve body issue, but I have yet to open it up. I'm open to switching out some solenoids and maybe even cleaning up the valve body, but I have no idea how much is easily accessible and doable for the young DIYer. I'll be going off to college in August and the ole TB will be staying behind and I'd like everything to be as perfect as possible by then so my parents won't be tempted to go to a local mechanic, of which there are few we haven't been screwed over by.

As I change the transmission fluid, what would all of you who are much more experienced with the 4L60E suggest replacing and/or servicing while I have the pan down?

 

[Drec]

It would interesting to know if there were any mods done to your transmission when it was rebuilt before, if it was rebuilt. I was going to service my transmission, but it gave up before I had a chance. It was working good, then during a shift into fourth, it revved up and wasn't the same after that. The guy that rebuilt it showed me yesterday all of the parts that he replaced. I'm fairly handy, but after seeing what he ended up doing, it was probably best that I didn't take on a repair to it. As with everything else YMMV.

You might do a Trans service to it and see what it looks like though, it might be fine if you haven't had any problems with it.

 

[Reprise]

If the only issue is a firm 1-2 (assuming it hasn't always been somewhat firm), I would probably do a fluid / filter, install a trans cooler (sounds harder than it is), and call it a day.

Use a good synth fluid (Valvoline makes a good one that doesn't break the bank), and a good filter, like Wix. Make sure you get the right filter (look underneath; if the pan has a step or notch at the back, you have the 'deep' pan, as most of us do. Compare the length of the snout (pickup tube) of old / new filters; they should be the same, not 2 inches difference between them.) If the little black 'gasket' doesn't come out with the filter snout, just make sure it's still in the orifice (you'll be able to feel it), and reuse the existing - it's hard to get out, and really doesn't wear out. As long as the filter doesn't fall right back out (you'll feel it seat, just as you'll need to give a little tug to get the old one out.)

If the pan has a drain plug, use a 6-point socket on it; GM overtorqued most of them. If you can't remove it, you can do a traditional pan drain (it will be messy).

On the trans cooler, ther are kits available that will let you plumb a short tube adapter in so you don't have to cut (and flare) the metal supply tubes.

A good reason for putting in a cooler - if the trans fluid heats up enough (stop-n-go traffic jam midsummer, as I experienced) mom & dad will feel the 1-2 really get rough (slam) until it cools down again. Cooler the fluid, the longer the trans lives.

To me, those are the best, most effective things a smart but somewhat inexperienced person as yourself can do for the trans without getting in over your head. Expect to pay a little over $100 for everything. Get a 6th qt of fluid if you put in the cooler (but don't expect to use all of it unless it's a really big cooler.) And putting in the cooler after you get the new filter installed & the pan back on, right before the addition of the new fluid, is the most efficient way to do it. Expect an hour or so to do filter / fluid; add two more if you do the cooler (including some prep work to familiarize yourself, etc.)

 

[Mounce]

DIY trans flush as shown by a member here. Search it and there's lots of info here if you're really worried about a full, non-damaging trans fluid service. Flush machines are highly frowned upon, which is why most shops will make you sign a denial of guilt contract prior to the service to cover them when when your trans possibly blows a little down the road. Have seen no issues reported with the DIY method though and have done it myself.

Second iteration of his process on different vehicle, still a 4l60e though

 

[Mooseman]

We all started somewhere. I started on my dad's '74 Caprice with oil changes and brake jobs. Now I can do pretty much anything except rebuild trannys or diffs. All I did was buy manuals (no internet back then) and follow the instructions. You're basically doing the same thing.

Just out of curiosity, is the check engine light on with any codes?

All good advice above. Do a full fluid replacement as explained above with a new filter and add a cooler. See what happens. Any Dex VI fluid is good as it has to meet GM's specs to get that designation.

 

[Reprise]

For all the details I put in my posts, I sometimes leave out an item. This time it was about the fluid (thx to @Mooseman for the reminder).

Whichever fluid you use, get a specific labeled Dex VI, not a 'universal' / 'compatible with'. Also a reason I mentioned the Valvoline in my earlier post (no, I don't work for them!)

 

[03_LT_EXT_4X4]

@Drec - I would like to know that as well and I'll definitely take some pictures and do as much looking around as I can.

@Reprise - I already have the filter and fluid, six quarts Valvoline right now, though no drain plug. I've wanted to do a trans cooler for a while now, but line flaring has kept me away; I didn't know there were kits available with adapters so that would definitely help me out there. I did pick up Dex VI fluid and Valvoline, not that I work for them either haha.

@Mounce - I've read nearly every thread and watched most of the videos on Youtube for doing flushes and I've been considering it. Possible doing a fluid swap by dropping the pan, then adding in a cooler and doing a flush a little bit down the road once I'm confident everything is in order.

@Mooseman - I'm definitely not afraid to do work on the cars as I have (most likely misplaced) confidence in myself, but everything I've screwed up so far I've gotten myself out of pretty clean. Anyway, I swear our TB's CEL only works if the gas cap is loose. Whether it's the thermostat or a misfire, it almost never lights up. With that said, the CEL isn't on nor are there any codes or anything to be concerned about.

Thanks to all for the advice!! This week almost every single day is rain and I'll be working after school so I'll hopefully be getting on with everything by the weekend assuming the weather improves.

 

[Drec]

If you pull the pan, I'm sure someone here could give you pointers on what to look for. The are some pieces that are made of plastic that could be replaced along with some other weak components. That is why I asked about what might have been done before. Did your parents keep records of the last repair? That might tell what was done to it before.

 

[Mooseman]

For the cooler, no need for flaring. I just cut the line out of the radiator cooler with a pipe cutter and slipped the rubber hose over both ends with doubled hose clamps. No kit. In fact, I used a cooler I picked up from the pick-a-part. Only got some new hose and clamps.

 

[Drec]

For the cooler,.................

Do you still use the radiator cooler, or do you eliminate it?

 

[Mooseman]

I still use it in series with the aux. cooler.

 

[03_LT_EXT_4X4]

@Drec - The only record I know of for the new tranny was when I heard my parents on the phone with the dealer saying to just put a new transmission in. Whether that meant a reman or a genuinely new one I couldn't say or find any record.

@Mooseman - I'll definitely check out some salvage yards and see what I can find this weekend.

 

[cornchip]

For the cooler, no need for flaring. I just cut the line out of the radiator cooler with a pipe cutter and slipped the rubber hose over both ends with doubled hose clamps. No kit. In fact, I used a cooler I picked up from the pick-a-part. Only got some new hose and clamps.

I added a B&M cooler just the other week. Just make sure any hose you buy is 11/32" inside diameter so it fits tight on the existing tubing. I also used two 3/8" EFI hose clamps for all my connections.

 

[Mooseman]

Check with the dealer. They probably have a record of it and any.other work your parents had done it.

 

[03_LT_EXT_4X4]

@cornchip - Will do, thanks!

@Mooseman - I'll see if I can get any info from the dealer, but it's changed hands three times just since we had the transmission replaced.