AW4 doesn't start when cold

[sdg99]

My 96 Cherokee has the exact same problem!

It's winter in Australia now (50-60 degrees when I try start it) and after leaving it overnight or for a few hours I have to wait 5+ min for reverse to engage. Once it does it's fine, no other symptoms. The colder it's been, the longer I wait. Really cold, I have to push it back.

Forward is always good. I have asked the dealership to replace the filter and oil and it still happens, but I'm not sure what oil they used. They reckon the seals have hardened up and it needs a new clutch pack at stupid costs.

Please post back if you manage to solve it and how, thanks,
Sean

 

[Quarterwave]

Hi Sean, I used to live in Caringbah South (Sydney, N.S.W), and I know for a fact that the Jeep dealerships in Sydney know sweet F.A about the cars they sell and work on. Especially when it comes to them selling new parts over just fixing a simple problem.

My dad bought a brand new XJ in about 2000, and had so many problems with the Scuderia-Veloce approved service dept, that he sold it for a new (at the time) VT Commodore - for all you stateside readers, that's a 4 door version of the new Pontiac GTO over here.

P.M me and I'll send you to a good friend of mine if you're interested - you don't mention where you are based, and I think my friend's shop is in Moorebank now - FWIW, he's a reputable mechanic and will do the right thing by you.

Another option is to check out the Trading Post - I used to use a trans guy around the Roselands area that knew his job and was very reasonable (he used to advertise in that paper a lot). Just remember that the AW4 doesn't have a "replaceable" filter - it's a metal screen that just needs to be cleaned and re-installed, so if they give you the "you need a new filter" line, tell them to go away quickly using only two words.

Good luck with it all, and FWIW, don't be a stranger to this site, there are A LOT of good people that use this resource, and will save you big dollars if you can do things yourself. Jeeps over here are commonplace and for good reason - they are solid cars for the most part and have a devoted following.

 

[sacem]

Yesterday I stated that the pan did not had any gum like substance, I retract, the pan had a thin smooth gum like sooth adhered all over and the filter had much more, so the findings have been what was the experts diagnostic.

One question, I am cleaning the filter with gasoline several times and then flushing the rest of the gasoline with Dexron III so that the filter does not carry over any strange material (gasoline), am I right?

I'll keep you posted

SACEM

 

[sacem]

Final UPDATE on my problem:

I did what was told by all of you guys out there, and I recall:

- Change the AW4 fluid to DEXRON III/MERCON

- Clean the filter and pan

- Purge the lines after refilling with DEXRON III

- Run the car until at working temp

- Change AGAIN the fluid by draining completly and refilling with DEXRON III

And IT WORKS, it starts inmediatly, it backs likewise even when cold and I have saved me a lot of money (I thought I had to do a trans rebuild).

Thanks again

P.D. I plan on replacing the fluid in about 1K miles just to be on the safe side.

I can tell you how happy I am, I love my XJ and this crowd is just great

Thanks.

 

[Pioneer89XJ]

Final UPDATE on my problem:

I did what was told by all of you guys out there, and I recall:

- Change the AW4 fluid to DEXRON III/MERCON

- Clean the filter and pan

- Purge the lines after refilling with DEXRON III

- Run the car until at working temp

- Change AGAIN the fluid by draining completly and refilling with DEXRON III

And IT WORKS, it starts inmediatly, it backs likewise even when cold and I have saved me a lot of money (I thought I had to do a trans rebuild).

Thanks again

P.D. I plan on replacing the fluid in about 1K miles just to be on the safe side.

I can tell you how happy I am, I love my XJ and this crowd is just great

Thanks.

Great to hear it worked out!!!

Another reason to change the fluid in our AW4 frequently. I have pulled fluid (from the plug) from my AW4s in my 89 and 98 XJs at least a couple times a year and they have always shifted great. Fluid is cheap and its easy to do.

 

[sacem]

Well folks, here we are again on the same problem:

The Dexron III/MERCON fluid was in just 5 weeks ago and the shifts where really fine, I have been using the XJ about 3 weeks (been 2 weeks out of the country) and it started slwly to take more time to shift into reverse, just like it was before, until last Friday the XJ decided she only wanted to go forward, Reverse was not working AT ALL, I had to push it backwards to get her out of the parking lot I had arrived some minutes before, that is the AW4 was still warm so it should not have been a temp issue, ambient temp around here is about 70ºF.

Well back to the learned routine, drain the fluid, out the trans pan, out the filter and I found:

The DEXRON III/MERCON fluid was a dark chocolate in color, not thicker than new fluid, just dark brown instead of original redish color.

Some small pieces of cork came out with the fluid like the ones used on some gaskets.

The filter had the same sticky gum that we found before, it was cleaned and dried.

Trans filter reinstalled and pan fitted back with very thin sealant to avoid it entering into trans case.

We filled new DEXRON III/MERCON fluid, disconected the cooler line to the rad and started the engine, out came more dark colored fluid, we refilled clean fluid and out came dark color fluid that has been done several times (a full 5 gal DEXRON III fluid was used) and the color was still dark, a little bit lighter but not dexron red color.

Out with the XJ to buy more fluid IT BACK UP INMEDIATLY, so I was quite happy and bought another 5 gal bucket.

Back to filling and purging until color was a nice red dexron. Tried the trans and it backed inmediatly, again.

Shut down everything and cleaned things up.

Four hours latter I started the engine and it was shifted into REV and a small 5-6 second lag of time until it engaged in reverse, why, I do not know.

Today morning the car backed up with also a small delay and why does it work perfectly when fed just at that time new dexron fluid and why does it start taking more time as hours/days go by.

Any suggestions.

SACEM

 

[MyJeepXJ]

Early signs of trans failure, its happended to me twice (two different vehicles, 2 different trans). Eventually, its starts slipping all the time. Save some smack up for a rebuild.

The problem is the seals in the trans have gotten so bad, fluid is getting past them so as the pressure is not built up enough for proper operation. Grab any ATSM manual and look it up. 99% sure thats your situation.

Theres nothing you can do to resolve this, you will need an R&R soon. From your last post, likely VERY soon. Sorry.

BTW, the dark color of the ATF you drained, that means your trans has been toasted, the clutch packs are worn.

Good luck,
Andrew

 

[sacem]

Thanks MyJeepXJ.

I was hoping it was not that, even thou I had the same idea that you have about the trans rebuild.

The oil burned up by the clutches is as you say a sign of clutch slippage and the seal problem should be the cause of the lag in time when just started.

BTW I have noticed that when I park the XJ on an upward incline surface (front higher) the trans starts inmediatly, when the other way around then it really takes it time to start and when level it is variable from no delay to long delay.

I would like some leads as where I can find rebuiding kits for the trans and a clue of what should I need to buy for the rebuild as I think it will be cheaper for me to buy them directly in the states than from the dealer here.

Thanks again

SACEM

 

[Rob Mayercik]

I would like some leads as where I can find rebuiding kits for the trans and a clue of what should I need to buy for the rebuild as I think it will be cheaper for me to buy them directly in the states than from the dealer here.

Have you considered looking for a low-mile used unit? That might be cheaper, and get you on the road faster.

Are there any junkyards near you that might have a similar-vintage rig to yours that you could score a trans out of?

Rob

 

[sacem]

There are a huge number of XJ running around but usually here in Peru you will not send a unit to a junk yard unless it really was COMPLETLY DEMOLISHED, you will not believe the cars that get rebuilt in here, but your suggestion is not bad and I'll start looking around.

Thanks

SACEM