LT85 Sticks in First When Cold

[Inigo]

First thing in the morning, while gearbox is cold, first and second gear are very notchy and difficult to deselect.  Tried double declutching, but it feels as though something is trapped and it is getting worse.  This morning had to really struggle to get back out of first.

Once I've gone about 5 miles, and the gearbox is nice and warm, everything works as it should.  Still fine if I drive it again later in the day.

Gearbox was a refurb from Ashcroft and has only done a few thousand miles.  Maybe something was disturbed on fitting gearbox to new engine?

When engine is not running, it slots into and out of each gear beautifully.

Perhaps the extra torque from new engine has already damaged the gearbox.

 

Any ideas?  Or do I need to pull the whole thing out?

[Eightpot]

Try changing the oil and make sure it's the correct type.  Lt85s use 20/50 engine oil and it needs changing when you do the engine oil - around 6000 miles. 

[neil110]

you can use a whole array of engine oils in the LT85. 10W/30 10W/40 10W/50 15W/40 15W/50 20W/40 or 20W/50 

In winter, one of the thinner oils might be more beneficial though the manual suggests that 20/40 and 20/50 can be used down to -10.

If it has not been fitted long and is an Ashcroft overhaul why not contact them? they give 12 month unlimited mileage warranty

[Inigo]

Just had all the fluids changed by local indy, maybe I'll call them and ask what they used.  I may not have done many miles, but the gearbox has been in the vehicle for a few years now, so definitely outside warranty.

I'll have a look at the oil and check the level.

Thanks.

[Inigo]

Changed the oil again , made no difference.  Fitted a slickshift, bu this might have made things worse - still tricky to engage first and second when cold, but now reverse requires two hands to force it in.  I understand that adjusting the bias springs can make reverse easier to engage, but there is almost no springiness returning gearstick to center, I assumed that tightening bias springs further will make Reverse even harder to engage.

Having read the overhaul manual, it looks as though I need to remove the top cover and re-adjust the selector forks.  Is this possible with the gearbox still in the vehicle?

[lo-fi]

Is the clutch biting low? Sounds like it might not be disengaging completely. 

My LT85 is a bit notchy when cold on 20W50, but not so bad in the summer. I have to make sure I'm not being lazy with the clutch or it's quite sticky until warm. 

[mickeyw]

Something to bear in mind - the LT85 does not do fast gear changes. It's a pretty agricultural box with quite some throw on the lever.

How long have you had this vehicle? Is this a problem that has occurred recently or are you new to the peculiarities of the LT85?

I'd be looking at clutch pedal travel. Every time I find a shift a bit hard work I remind myself to push the pedal all the way to the floor. A  deliberate and unhurried clutch pedal movement can give a pretty smooth lever move and take up of drive. If your clutch pedal isn't adjusted right it won't help matters.

Homing in for a moment on your mention of having fitted a Slick shift - as far as I am aware they don't make one for the LT85. I remember asking Shabs Piercy if he planned to make an LT85 version when he first launched the product, and he answered to the negative. Is you box definitely this model?

[Inigo]

I've had the vehicle for quite a few years, but not done that many miles.  I had that box refurbed early on in my ownership and it was silky smooth at first.  Notchiness was after it was refitted with a new clutch, so could be related to that, clutch had to be balanced and, I don't recall exactly, but there were some issues getting it to work.

Looks like I should investigate that area.

It certainly is an LT85 and the previous time I looked there wasn't a slickshift for it, I just happened to come across it on their website recently and thought it might help, but, as you say it just reduces the throw.

Having put a few more miles on it over the last day or two, it seems to be settling down a little.  Reverse is now not much worse than it was before.  Once warm, it all works quite smoothly.

[mickeyw]

Hmmm..... a clutch should be supplied balanced out of the box, and as long as your flywheel has the requisite locating dowels it should be running true when attached to that.

As lo-fi asked, is the bite point a long way down in relation to pedal travel? If so, this can be adjusted on the master cylinder push rod to pedal connection.

 

This shows to adjusting process.

I wouldn't get too focused on the dimensions, but they are a starting point. The drawing is of a 300Tdi Defender pedal. If you have the early pedal type the dims may be  bit different. Ultimately I would aim to achieve what functions best.

[Oakmaster]

On 8/8/2019 at 1:13 PM, mickeyw said:

Something to bear in mind - the LT85 does not do fast gear changes. It's a pretty agricultural box with quite some throw on the lever.

How long have you had this vehicle? Is this a problem that has occurred recently or are you new to the peculiarities of the LT85?

I'd be looking at clutch pedal travel. Every time I find a shift a bit hard work I remind myself to push the pedal all the way to the floor. A  deliberate and unhurried clutch pedal movement can give a pretty smooth lever move and take up of drive. If your clutch pedal isn't adjusted right it won't help matters.

Homing in for a moment on your mention of having fitted a Slick shift - as far as I am aware they don't make one for the LT85. I remember asking Shabs Piercy if he planned to make an LT85 version when he first launched the product, and he answered to the negative. Is you box definitely this model?

Ive been gently nudging Shabs to make an LT85 slick shift - maybe we need to form a lobbing group?

(apologies -didnt mean to Hijack the thread) 

[Inigo]

I'm not imagining it, but it is well hidden on his website: https://www.onlinegearboxparts.com/product/defender-lt85-slickshift/

[mickeyw]

15 hours ago, Inigo said:

I'm not imagining it, but it is well hidden on his website: https://www.onlinegearboxparts.com/product/defender-lt85-slickshift/

Well found. I looked yesterday and didn't see it.

I have to say that I am not sold on the idea of this product. I get the idea that it reduces the throw, making it a little closer to that of a normal car, but I would expect (I haven't driven a vehicle with one fitted) it to require more effort to operate. 

The biggest improvement I made to my V8 110's gear shift was the addition of a vacuum servo on the clutch pedal. I don't really find the throw of the stick an issue.

[Inigo]

Well I was going to take the top off the gearbox anyway to change bushes/any worn parts as my limited experience with tricky to shift gearboxes was replacing worn plastic parts in a triumph herald.  A friend suggested that if I was going to replace some components anyway (and the cup that the standard shifter sits in is £90) then I may as well go for a slickshift.  He has one on his TD5 and loves it.

I found the throw a little shorter, but I wasn't bothered by the longer throw originally.

Other minor advantage is that stick no longer bashes against mud dash when I'm less careful.

[Lightning]

I tell you what, we had exactly the same fault on our 300tdi and after replacing the gearbox selectors, master cylinder and slave cylinder (which made no difference whatsoever)

As a last resort l was about to replace the gearbox completely

lt turned out to be the clutch. After a new one was fitted, it was transformed and the gears engaged smooth as butter.

Edited August 10, 2019 by Lightning