1HDT 80 purchase, advice on gearbox?

Re gearbox, they are fussy about oils.

Change to 75/85 - either Castrol VMX-M or Valvoline Duragear and I think you'll find the cold shifting will improve.

Ben,
I'll second what Phil said about oil, I changed to Castrol VMX-M in a 96 80 series DX and the cold shift is 100% better. Try new oil first.

Cheers Drew

Ditto, Castrol VMX-80 nothing else.
TB

I concur......VMX is the go.

vmx or dq dextron in an auto :)

www.lcool.org worth reading for any and all things 80 series ,

Ben, the early 80 series had a problem with the second gear syncros and if owners complained enough during the warranty period the dealer would strip and replace the second gear syncro hub with a hub that had two synco cones, as your car is 15 years out of warranty there may not be a cheap way out of it.
I suggest changing the oil to what the others have recommended and if that does not fix it either learn to double shuffle or rebuild the box and ensure that the mod is done on the box also investigate installing a new box from Toyota as I have seen some rebuilds cost more than a new box.
Hare'y

Many thanks to you all. I'll try the VMX and see if it improves. I don't do any city driving so its not too much of an issue, just needed to know my gearbox was going to die on me in the near future. Any of you have similar knowledge on the eldorados?
Thanks again, Ben

Hi Ben,

As mentioned above changing the oil will make the world of difference.

My gearbox feels beautiful to use when the oil is warm, it is nice and smooth and dead quiet but that first change to 2nd gear in the morning is very difficult to get it in. Someone above mentioned double-clutching to get it in but with my gearbox this doesn't work.

I get around it just by taking off in 2nd gear first thing in the morning. I have no problems with the 2nd to 3rd gear change when it is cold. As you said once there is a bit of temperature in the gearox oil the problem goes away. It certainly is not something you should be concerned about and it is not an indication that your gearbox or synchros are on the way out. It is a well known issue and most seem to just live with the problem when it is cold.

I see you have said you replaced your front hubs to help eliminate the drive train backlash issue. Mine is also a 1990 model with backlash isues. When you say "hubs" does this mean the CV joints are what you replaced? If so did you fit standard CV's or did you upgrade to the post '94 model CV's which are a bit beefier? As I also have a singing front diff I am tempted to just get a complete disk to disk front axle assembly from a post '94 model as this may be cheaper than replacing the CV's and diff centre and would also give me the bigger brakes of the later models at the same time. As i do a lot of heavy towing the bigger brakes would come in handy.

Regards,
Brett

You need to change your name now ! - 90 cruiser ?

Big Woody,

We seem to have very similar issues. My mechanic initially thought my drivetrain slack was an issue with the front diff. Soon found out from a friend that pre 94 or 95 it was a problem with the hubs in the AWD models. Apparently the splines on the hubs aren't very 'deep' for want of a better word and wear down over time, causing the slack and the clunk in the driveline. The hubs seem to go first and since mine have been replaced, it has all but eliminated the issue. If you pull the wheels off, I'm told you will be able to twist the hub to make sure it is your problem. Sorry if I'm a bit vague but I didn't do any of the above myself, it was done by my mechanic when the roadworthy was done.
I saw a week or so ago on ebay, the hubs for sale where the seller goes into depth about the problem, obviously new items. I'm yet to change the oil in the gearbox but will do so and get back to you.

Ben
ps God knows how to change my name, (93 Navara) tried and failed. Think I might have reapply to become a member.