Hi all, I’m in desperate need of a solution to my gearbox problems.
The problems started when 3rd, 4th and 9th and 10th gears are jumping out of gear.
The gearbox has been rebuilt and re-calibrated four weeks ago.
This cured the problem, and the gearbox has never been better.
I took a one week holiday, came back to work, and the same problem is back.
I returned the truck to the gearbox repairers, where they have removed the gearbox, checked it throughout, and re-calibrated it. They have assured me that it is not the gearbox that is at fault and is in perfect condition.
So far this has cost me three weeks work and a lot of money.
just to clarify, this is the ishift box.
Thanks in advance! 
If it’s a manual gearbox we’re talking about, then I’d say one of the selector cables is on the point of snapping.
Thanks Harry, it is the ishift box. I’ve edited the original post.
I can verify that the box is in perfect condition inside.
have you had it at volvo on the lap top to match it up to the truck
Yes, and it is showing “no faults”.
I don’t wish to be the bearer of bad news, but it honestly sounds to me like the gearbox repairer has ripped you off and done a “Jizer and paint” recon.
Is air pressure ok?
Own Account Driver:
Is air pressure ok?
Why do you ask that?.. 
. Strangely enough, it could be the answer, as when the problem started, the truck had stood for a week, had the gearbox rebuilt (and they couldn’t find any faults). The truck has been fine, stood for another week and the problem returns.
Checked the box again, re-calibrates okay, but the problem is still there.
I am still in need of answers please
From what you have described you seem to have covered all the bases. I don’t know enough about I shift gearboxes to offer a solution, I rely on my local Volvo dealer and gearbox repairer to diagnose and repair and over the last 12 years I’ve used the I shift any problems have been diagnosed 100% correctly by Volvo.
When you had it in volvos did they suggest anything?
As for air pressure I’ve had faults with gearbox lids due to crap and moisture coming from the air tanks blocking airways up. Do your air tanks drain completely clear, no water,snot or oil?
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According to our fitter, air quality is very important to i shifts running smoothly, and why he changes air drier cartridges regularly.
Thanks Coiler, it looks like my only option now.
The strange thing is, that when it first started, it was the day I came back from a week off, and I went back to work on Monday after a week off and it’s done exactly the same… Very strange.
When I’ve spoke to Volvo, they have said that they would probably strip the box again and start from scratch, but I know for a fact that the box is okay.
There is no fluid in the tanks, but it is dropping the air overnight. There are no leaks from the top of the box, and no audible signs of air leaks.
skelly:
According to our fitter, air quality is very important to i shifts running smoothly, and why he changes air drier cartridges regularly.
Thanks Skelly, it could be an issue… I do think my air drier is on its way out.
A small point to note… If I floor it in the gears that it is jumping out of, it’s okay, but as soon as I take my foot of the pedal slightly, it jumps out of gear… Maybe that could be because it is pumping more air through the system
Bit of a redundant reply now as you get the gist from the others.
Yes, not just ishift but most autos all need clean, dry and good pressure air. Often the gearbox rebuilding places will have some sort of test rig that tells them the box is ok. Assuming the box is ok if there’s problems when it goes back in the truck often it turns out to be some sort of sickness in the air system but do always bear in mind the box may not be right but checking everything is right with the air system is where I’d start.
Okay, I’ve left my truck at the Volvo garage, and as of now, they are stumped by the problem.
So it’s a long weekend for me, and probably a big bill… So bollox to it. I’m off to Scarborough for the bike racing. Hopefully when I come back, I’ll know the outcome!
Any news yet?
skelly:
According to our fitter, air quality is very important to i shifts running smoothly, and why he changes air drier cartridges regularly.
What does he consider “regularly” ?, I do mine every six months.
Stanley Mitchell:
skelly:
According to our fitter, air quality is very important to i shifts running smoothly, and why he changes air drier cartridges regularly.What does he consider “regularly” ?, I do mine every six months.
I wouldn’t change it anymore regularly than that should be fine.
Own Account Driver:
Stanley Mitchell:
skelly:
According to our fitter, air quality is very important to i shifts running smoothly, and why he changes air drier cartridges regularly.What does he consider “regularly” ?, I do mine every six months.
I wouldn’t change it anymore regularly than that should be fine.
Thought so, as I`ve not had any problems with this schedule 