Dexron and transmission delay

[Kevin.G]

Good day all, I'll try to keep this short regarding my '05 3.7 Liberty KJ. Swapped my 42RLE transmission with exactly the same from a "spare" vehicle with a "good" transmission. Replacement box was flushed and refilled and new filter installed, smooth and quiet operation through all gears, both start-stop and open road. Here's the problem - when cold all is good, after a decent run and fluid is hot, when idling stationery, there is a serious delay when engaging either R or D from N (but only when hot, and there is no noticeable slip or delay whilst driving, and there are no error codes displayed). Now, here's the curved ball - the workshop that carried out the work recommended/convinced me to use Dexron VI. Will this cause the excessive delay in engaging gears? Please help with advice.

 

[eric1514]

It could very well cause your problems and long term, I can't imagine it would be good for it. If the Factory Manual says to use ATF +4, I'd flush the Dexron.

 

[Kevin.G]

It could very well cause your problems and long term, I can't imagine it would be good for it. If the Factory Manual says to use ATF +4, I'd flush the Dexron.

Thanks Eric. My thoughts exactly. I suppose that means a new filter as well? How do I make sure all the old Dexron is out before the final fill with +4? Is there a step-by-step somewhere I can follow?

Just a follow on question from the above - the transfer case was also filled with Dexron 6, is this as serious as the transmission or can I get away with this one?

 

[eric1514]

I'm going to flush my transmission because the fluid is old. The first time I'm going to drop the pan and change the filter for the same reason. Your filter is new so maybe skip that. You are never going to remove all the old fluid, but you can get close.

Either way, I would look for a small fluid extractor pump like this

LINK

and suck the fluid out through the dipstick. Draw out 4 quarts and replace 4 quarts. Drive around and repeat. After 5 times, you will have almost 90% ATF+4 in there. You don't have to do this all in one day. (new fluid %=1-(2/3)^n). You will make almost zero mess doing this and you won't have to crawl under the car. The more often you do it, the closer to 100% you'll get. I plan on getting to this point and then doing 4 quarts every time I do an oil change. Think of it this way. Even when you perform a regular oil change, you can never remove all the old oil.

Or you can pay someplace to flush it. I don't know what that runs or if I trust them to do it right. NAPA sells Valvoline ATF+4 for around $7.70/quart. Your cost would be around $200 for the fluid and the pump. And you'd know you used the right stuff.

And yes, change the transfer case fluid, also.

 

[Kevin.G]

Thank you for this. I live in remote part of South Africa, so back and forth to the workshop is not really practical, and I don't exactly have a clean ideal place to work. I remember reading somewhere that a sump plug can be fitted to the 42RLE pan. Any thoughts or advice?

 

[eric1514]

There are aftermarket pans with drain plugs. That is certainly an option but the results will be the same. You cannot remove all the fluid by opening that drain, or dropping the pan, for that matter. The bulk of the oil will remain in the transmission and will subsequently mix with the new fluid. You will have to repeat the process.

 

[Shankster]

I would consider that negligence on the part of the shop. Betting they just didn't have the right fluid on hand so gave you what they had. At a minimum you should get a full refund - not sure I'd want them doing the work over with the ATF+4 though since they obviously can't be trusted. Maybe try sending an email to Jeep and ask them to give their opinion on the use of the Dextron and present that to the shop when you demand your refund. If they're jerks about it I'd take them to small claims court (if you have an equivalent in South Africa) and have them cover the additional costs too. I agree with the above that you'll want to get as much of the Dextron out as possible - won't be cheap considering how many drain and fills you'll need to do to achieve that.

The transfer case shouldn't be such a big deal but I'd definitely get that changed to ATF+4 as well.

Note that the power steering fluid should also be ATF+4 - I believe I trashed my original pump by using generic PS fluid so I think that is a big deal too.

 

[Kevin.G]

Thank you so much for all the advice. it really is a problem living out in the middle of nowhere and being at the mercy of those "in the know". I will see if I can get the workshop to drain, flush and refill the box with correct ATF+4 then give feedback on whether this sorted the delay problem. While they are about it they will have to attend to the 4WD selection which is not engaging 4H, they can't seem to get that right either.

 

[always wrenchin]

This is an option as well

https://www.ausjeepoffroad.com/forum/forum/jeep-garage/xj-mj-cherokee/85355-flushing-auto-transmission-poor-man-s-flush

 

[Shankster]

This is an option as well

https://www.ausjeepoffroad.com/forum/forum/jeep-garage/xj-mj-cherokee/85355-flushing-auto-transmission-poor-man-s-flush

I would NOT do that. On the recommendation of a friend I once did the same thing to the family minivan and the transmission failed a week or so later.

 

[24turbo]

I would NOT do that. On the recommendation of a friend I once did the same thing to the family minivan and the transmission failed a week or so later.

This^^^

Many transmissions use the return from the cooler as the lubrication circuit. If you interrupt that flow any moving parts in the transmission when idling will not get any oil flow.



A proper flushing machine does tie into the cooler line but adds oil to the transmission return at the same time it’s removing oil so the circuit is still intact.

As for the Dexron in the transfer case, I wouldn’t worry about it at all. If you want to run a better fluid, Royal Purple Synchromesh ( if available in SA) is a good choice.

 

[Kevin.G]

Thanks once again for the advice. I have paid good money for the work done on the transmission, so I will insist the workshop does the job, even if I have to stand there and make sure the flushing is done done correctly.

As for the royal Purple, it is available in one location only in the country at US$75 per quart excluding shipping to my location!!!

 

[Shankster]

This is from the 05 shop manual (at the time it was written I'm assuming Dexron II was the latest evolution)

You must be registered for see images attach

 

[24turbo]

Thanks once again for the advice. I have paid good money for the work done on the transmission, so I will insist the workshop does the job, even if I have to stand there and make sure the flushing is done done correctly.

As for the royal Purple, it is available in one location only in the country at US$75 per quart excluding shipping to my location!!!

Yikes that is pricey. Most all major oil companies have something equivalent to that at a much lower cost.

The only reason ATF is specified is the factory doesn’t want to stock anymore types of oil than it has to. They already have ATF+4 on site so if it’s “good enough” that’s what it will get. There are better oils for transfer cases but it does the job.

These transfer cases have no clutches at all, just roller bearings, gears and a chain so its only job is to lubricate these components. Pretty much any ATF would work, synchromesh fluid or even ISO 32 hydraulic oil from a tractor. Some suggest motor oil but personally I think it’s the worst choice ( but it does work)

 

[Kevin.G]

Thanks. I agree, the transfer case is not as sensitive as the 42RLE. So, my focus for now is to overcome the crazy delay when engaging D or N when hot. First stop, drain, flush, then get the correct fluid in and hopefully that will take care of it?

 

[Kevin.G]

So... the workshop that filled the box with Dextron 6 is maintaining under good "authority" that this fluid will be fine in the 42RLE and will not be the reason for the delay shifting problem I have, but rather a learning issue causing the problem after the transmission swap. Is there merit in this argument bearing in mind the delay only occurs when the box is hot, not when cold?

 

[24turbo]

Not sure if it’s causing your issue but yes you definitely need to do a re- learn if you changed or rebuilt the transmission. They should have done that when it was installed.

Sounds like you probably won’t get any satisfaction from them so you may just have to get it done yourself or by a different shop.

I had read somewhere that there is an additive that will make Dexron the same as atf+4.

 

[24turbo]

Also another thought on your specific delay problem.

Any shop that has a scanner capable of doing a relearn can check clutch volume index (cvi). It essentially will tell you how worn out your clutch packs are by the volume of transmission fluid it requires to apply the clutch. May provide some insight to you problem if one of them is out of spec.

 

[Kevin.G]

Thank you for the advice. I know they did do a general re-learn but not a a detailed procedure when I went back to them. Never fixed the delay problem though.

An additive to bring Dexron 6 up to ATF +4 spec? That's interesting. I wonder if anyone on the forum has tried this?

 

[24turbo]

“To make Dexron-VI compatible with Chrysler ATF+4, the most recommended additive is Lubegard Platinum High-Performance ATF Protectant (63010). It is specifically designed to convert non-highly friction-modified fluids (like Dexron VI) to meet the frictional requirements of ATF+4. [1, 2, 3] “



Based on google. Take it for what it is worth……

I read somewhere not too long ago on a forum a transmission rebuilder just used an additive. I thought it was a different brand but can’t remember what it was.