Risk in using conventional 10w-30 in AX-5 trans
 

Hi all - looking for some opinion for those who are familiar with the AX-5 transmission and gear / motor oil viscosity, etc. I recently had my AX-5 transmission fluid changed and the shop put in 10w-30 (I'm not sure if it was conventional or synthetic, so lets say worse case it's conventional). My shifting into gears seems fine, but I noted a whine in 5th gear when I'm on the gas that I didn't hear before (or at least not as loud). I also noted I can hear the transmission when I move through the gears with the car off or in neutral.

I'm thinking about changing to Synchromesh (after confirming it's ok for brass synchros) or the oft-recommended Redline gear oil or Amisoil, but finances, time, and weather are not in my favor at the moment. It seems 10w-30 is not the thing for my AX-5, just based on the feel pre & post change.

My question to you is, am I running a risk by waiting a bit (say a month / 1000mi) to change it over? Would there be a subatantial difference over that time between conventional and synthetic 10w-30?

I don't think 1000 miles would harm it much, but 10-30 is a lot thinner than the gear oil that should be in there.

If you get a fluid pump, you could pump it out of there and then replace it in about 15 minutes. Pretty easy.

I would change it now
Just my opinion

i would get the right lube and get it in there. a lot better on your finances than a new tranny.

Just to be clear, 10w-30 is the new spec lube for the AX-5. They put it in after consulting with their Chrysler guy who confirmed this. However, something just doesn't feel right after the change.

I just got under it and took a look at the fill bolt to see if I could get it out - I couldn't and started to round it off. This has me afraid maybe they underfilled it by filling at the infamous "do not remove" bolt on the drivers side...

Number one use the proper tool & size to remove the bolt and you should "Never" round off the edges of it. I hate it when people use the improper tools and ruin fasteners like that making it a real PITA to remove easily.

If Chrysler said the proper lube was 10w30 then that is what I would use and in "Real Dyno Oil". Between them and the transmission shop I would not second guess them with something else.

BTW buy yourself some tools if your going to do any work on your XJ. A screwdriver and pair of pliers does not amount to a tool set, and yes you need metric and sae wrenches, sockets, allen, torx. to work on the basics.

X2 on tools. If funds are low try and borrow when ya need em. For years I used harbor freight wrenches and sockets with craftsman rachets. I stepped up last year and got a Matco set/box. Large investment but it's something my kids will be using when they are older.

I hear ya on that. I didn't completely round it off - I was trying a crescent wrench as my socket +socket wrench wouldn't fit. I stopped once I noted a bit of rounding taking place. the shop said they'd put it up tomorrow and take a look, so that makes me feel a bit better. I may have them put some Synchromesh in at that time as well, if I come to the conclusion it's ok for the Ax-5 (lots of opinion on that as well).

It seems some AX5s are for the better with 10w-30 - some are not. There is also some opinion that, although 10w-30 is the "new" spec for that transmission, it may not be best option.

Seems like a huge change in viscosity. My 89 AX-5 FSM says 3.3L of 75W90 GL-5 gear lubricant. If you google search, you get all sorts of conflicting information (like using 75W90 GL-3, GL-4 etc, Pennzoil Synchromesh, etc).

Seems like most are arguing that 75W90 GL-4 is better for manual synchronized transmissions. This link has an interesting article. It's so hard to tell what is advertising hype and what is scientifically accurate when it comes to any lubricants. Engine oil should be for engines and gear oils for gears it would seem hard to reconcile using engine oil in a gear box but maybe a transmission is a hybrid.


http://www.widman.biz/uploads/Transaxle_oil.pdf

Totally agree - my head is spinning trying to figure out the best stop gap. I have a chance to switch it out tomorrow to synchromesh for short $$. Is that the right call? Who knows.

As far as GL5 in an AX5, I've run across a lot of chatter that the FSM was WRONG on that and that AX5s should have GL3 or GL4 (or, of course 10w-30) in them, as the sulpher additive in most GL5 degrades the brass synchros. You may want to look into that.