Auto trans service, DIY or not?

[85L200Express]

So my auto trans is overdue for a service. How difficult is it to DIY? Or am I better leaving it up to the professionals? It hasn't been done as far as I know for maybe 90k. Is a flush necessary? I'm worried, as I've heard flushes can do more harm than good. Is this true? Thanks

[benckj]

Good idea to do and complete yourself. Flush is not hard or risky to do as you simply extract as much fluid as possible by removing trans cooler line to drain, refill trans, drive and repeat. If you use a multi vehicle trans fluid like Penrite FS it is a reasonable approach. Think mine cost around $125 to completely flush and fill.

[P4J3R0]

It’s pretty straight forward to do an transmission oil change. Doing a filter change is a bit more complex.

There is a write up for the transmission filter and oil change here. https://www2.pajeroclub.com.au/forum...ad.php?t=15879

[4ndy]

So the procedure is the same for GEN3 and GEN4's?


Hmmmm infact I don't seem to have a dipstick for the gearbox?

[85L200Express]

Yeah, there's no dipstick on NT...

[Hatto]

What vehicle are you wanting to do it on? Your L200 or a gen 4 pajero? Petrol or diesel?
I'd love to see a detailed write up on a gen 4 tranny flush and filter change! Just bear in mind the gen 3 uses a different transmission to the diesel gen 4 pajero's. The fluid requirements for both transmissions are different to. Most say to use only genuine fluid in the Aisin transmission (gen 4 diesel) as they are super sensitive to incorrect fluid. However I have read of others I think using a penrite oil that met the right specs.
If I can find a write up with pictures on how to do it, I'll be finding a cheaper oil than genuine stuff! I think it's like $450 for a 20L drum!
Watching this thread with interest.

[85L200Express]

This is for my 2009 NT diesel Pajero. I was considering getting a flush but as I don't know the auto box history or how hard it's been treated I'm reluctant to get a flush completed in case it removes the gunk that is holding it together!

I emailed my local Mitsi dealer and they said that they would just do the service twice in order to flush it anyway! I was a bit shocked, I thought that they'd have a proper flushing machine, but this is probably the safer method anyway.

They quoted $390.00 per service.

I reckon I'll do it myself, but I'm going to wait until spring as the weather is too terrible down here in Tassie and I don't want to risk contaminants entering the box while I work on it as I only have my incline driveway to work in

[wazznt]

I emailed my local Mitsi dealer and they said that they would just do the service twice in order to flush it anyway!

Sounds like the dumb illogical thing a dealer might say , an auto trans specialist can do a full flush and filter change properly first time without needing to do it twice .

[benckj]

Doing service twice is how many garages complete this job. Power flushing doesn’t really accomplish much more and wastes as much fluid. Better off IMO to source less inexpensive fluid and do yourself. The Penrite range have great products to choose from.

[kiwi1973]

The way the Mitsi dealers do an auto service leaves a lot to be desired in my opinion. Their standard approach (some may do better) is to just drop the pan and replace the filter, then top up with as much ATF fluid as was taken out. However, only about 50% at most of the fluid in the overall transmission is in in the pan! So you immediately end up with a 50/50 mix of old and new ATF fluid. Repeating this same method is a very poor way to attempt to achieve a greater proportion of new ATF fluid in the transmission - the best you would achieved is about 75% new to 25% old. A flush is easier, faster, cheaper and far more effective.

I've done a couple of flushes myself at the ATF cooler lines in front of the radiator. When done correctly you can actually see when the old ATF fluid is out and fresh new ATF is coming through. But you need up to 12 litres of ATF to do this properly.

Both the Aisan and the Jatco auto transmissions are very sensitive to having the correct ATF fluid - and incredibly a number of supposed auto trans specialists still don't seem to know this and can use the wrong fluid, which leads to major issues down the track. The Jatco needs an SPIII equivalent ATF fluid, but doesn't have to be Mitsubishi Diaqueen, as aftermarket brands like Penrite produce a high quality fully synthetic product. If you have the Aisan transmission it's a different ATF fluid - check on here or in your handbook for the correct specs. Early Gen 4 diesels (NS) still used the Jatco transmission. So don't assume you have the Aisan just because you have a Gen 4!

The only part of this whole equation is the debatable issue of whether the filter/strainer in the pan actually really needs replacing? The mitsubishi dealer that I contacted some time ago for an explanation of what their transmission service entails commented that they didn't actually replace the filter/strainer! They went to all the trouble of dropping the pan just to change fluid - this is a hopelessly ineffective method if you just want to replace the fluid.

The reason I suggest it is debatable as to whether the filter / strainer truly needs replacement is that I understand it not to be a filter in the the traditional sense (not like an oil, fuel or air filter), but rather a gauze strainer. A while back someone on here who was about to replace their transmission filter was going to post up some photos of the strainer so that we might all get a better idea as to whether its replacement was truly essential. Be great if anyone who's done this has some photos of a used filter/strainer to post.

[benckj]

I’ve bought a spare filter/strainer but yet to install. Figured I’d do one flush then drive for a year, drop pan to clean and install filter then refill with new oil. My oil isn’t looking too bad and I don’t do any long range towing.

By my observations dropping oil from drain in pan plus pulling cooler hose to power flush oil out there is approx 6 litres removed. If the pan and filter removed another 1 litre is removed leaving about 2.5 still in box. Hard to get out unless torque converter physically removed. As long as the oil isn’t left well beyond the service intervals I think this approach is fine. As one Ozzy 4wd driver indicated he replaces about 4 litres of trans fluid every other oil change to keep fluid quality in check.

[jimako]

Is it the Toyota Prado that uses the same Aisin transmission ?
Has anyone looked up the cost and what toyota does for a trans service ?

[gaz1]

I’ve bought a spare filter/strainer but yet to install. Figured I’d do one flush then drive for a year, drop pan to clean and install filter then refill with new oil. My oil isn’t looking too bad and I don’t do any long range towing.

By my observations dropping oil from drain in pan plus pulling cooler hose to power flush oil out there is approx 6 litres removed. If the pan and filter removed another 1 litre is removed leaving about 2.5 still in box. Hard to get out unless torque converter physically removed. As long as the oil isn’t left well beyond the service intervals I think this approach is fine. As one Ozzy 4wd driver indicated he replaces about 4 litres of trans fluid every other oil change to keep fluid quality in check.

Any chance of a picture of the new filter/strainer? The discussion about what it actually consists of (filter or strainer) in the Jatco box has been going on for several years without a real outcome. I for one would love to know, and a picture could help resolve it.

[benckj]

I’ll see what I can with pic. It’s not OEM and from memory cannot see inside so not sure if pic will help.

[wazznt]

Is it the Toyota Prado that uses the same Aisin transmission ?
Has anyone looked up the cost and what toyota does for a trans service ?

If I remember correctly on my last auto service they fitted a Toyota {Landcruiser ?} filter ,somethings wrong if Toyota parts are cheaper.