So I am considering draining my transmission oil and refilling it with fresh oil.

I plan to use 50% Lucas oil Stabilizer. (good idea, bad idea?) your thoughts are welcome on this. I have yet to read anything negative on this product.

I am looking for ideas on the best oil to use in my tranny. What do the tranny gurus recommend for the Isuzu 5 speed from an 87 w/duke.

The transmission has never had any signs of problems since I bought the car about 2 years ago. I am not sure when the last time the trans oil was changed and I am looking for piece of mind on this since I am also installing a new (re manufactured) Duke.

I am hesitant to go by my Hayne's manual in case their recommendation is outdated.

As always, Thanks for all your help!!

I have an 88 duke/isuzu coupe and also would like to know this for almost the exact same reason. I've been told that the product you want is called "Synchro-mesh", but I do not know where to get it or how well it works.

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If you can't be good, be good at it.

Friends don't let friends use oil additives. Put down the bottle and step away slowly!

Fill the transmission with straight synchromesh and be done with it. That's all you need. Mixing it with anything else is just a bad idea.

http://www.bobistheoilguy.c...ages/lucas/lucas.htm - Have a look at this for one of the reasons why.

The Isuzu should have no problem holding up under a stock or even heavily (hah!) modified 'duke.

Jax184,

Thanks that was a good read. So syncromesh it is. Are there variations of syncromesh like conventional or synthetic, different viscosities etc... or is there only one syncromesh?

Thanks

Head to your closest GM Dealer, and pick up 2 quarts of Syncromesh for a Manual Transmission. It is the only kind they have in stock.

About 25 bucks total for both.

Great, Thank you for the info.

Pennzoil also makes synchromesh oil. You should be able to find it at your local auto parts store. I paid about $6 per quart at Auto Zone.

[This message has been edited by Blacktree (edited 10-08-2007).]

Is the Pennzoil stuff as good?

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If you can't be good, be good at it.

Thats what I put in mine also. Just above $6.00 at NAPA. I suspect one company makes it all, and just puts it into different colored and labeled containers for different sellers.