80series wont change down to 2nd

My GU does that when the box is cold going from reverse to first after about 20 seconds it's good....seems to only happen on very cold mornings

BayBreeze,

How old is it? Mine is 250K and all gears works flawlessly. Most likely that synchro-rings get a bit worn out – I use to have similar problem with my old truck, though with 3-rd one. It was going on for 150K and I just learn myself to make proper delay when changing to 3-rd. Good quality oil may mask that effect, but it will not go away until you rebuilt gearbox. I would live it unless other problem developed.

Cheers
Serg

Castrol VMX-M gearbox oil is recommended on lcool.org forums to improve the problem you are having. Other than that unfortunately it could be gearbox rebuild time

As above, change gearoil to Castrol VMX-M.

Have you had the gearbox serviced recently, or ever?

That would be my first port of call, get the system flushed, well worth its weight in gold.

Will it change when you manually shift it?

Also where are you located. if in Melbourne, give Rodney a call at Wholesale Automatics.

completly normal VXM-M may help but wont necc fix it
learn how to double clutch

A lot of truck gearboxs are the samewhen cold, either double clutch or change the oil as recommended above.
Cheers Pete

Can someone tell me why you have to double clutch a full synchro box?

BayBreeze

There is an off chance that it could be a repeat of a fairly common problem we had on the 60 series when I used to work for a Toyota dealer years ago.

The plastic seat that the gear lever ball sits in would slowly break up over a few years and allow the lever to sink down a little. This would cause binding in the selectors and make it very difficult to select some gears.

All we did was lift the lever out, pull the old seat out with long nose pliers from memory and drop a new one in. The loose fragments of the old seat that had often fallen into the box did not cause any harm.

I don't know if the 80 series is the same because I have never worked on them but the lever ball must be sitting in something so it might be worth having a look.

You could try pulling up hard on the lever next time you try it although this might not be a reliable indication because the spring on top of the ball is fairly stiff. If it goes in though then it is most likely the seat.

Brian

I've been living with the same problem for the past 5 years on my 80 series. Mine can be difficult to change from 4th to 3rd and 3rd to 2nd so as other have said I double de clutch, especially when the gearbox is cold. I have changed oils etc but that doesn't resolve anything. I intend to live with the problem until I have more serious problems such as replacing the clutch one day.

Toolman