LT77 is a pain when cold!!

[tetlow]

I have a LT77 that has only done about 5000 miles.

She broke last year and went back to the builder for a check over. All was found OK. Since then I have only done about 500 miles.

I use Redline MTL (not Cheap) but she is a real pain when cold. When warm the gearchange is OK.

Any suggestions? (Change of box is not on !!!!)

Dave

[sidecar]

I use MTL and on cold days the shift is slow, I just live with it and don't thrash the box or the engine until everything has warmed up nicely.

I look at this way, it's a small price to pay for knowing that you have a good oil in your box.

You could bung in ATF and get quick changes when cold but at what price?

[topcatcustom]

I just changed the oil in my LT77 and put thick Land Rover gear oil in- hopefully it will be ok..! Not in car yet so easy to do!

[ramon alban]

Hello Dave,

Here is a updated extract from a PDF on my website. I dont think you will need to use the flushing process with your low usage box but the lubricant in mine has been doin' its stuff for over a decade with never a sign of the original problems.

Radical Cure for a Nasty 5 Speed Manual Gearbox

• Here is a radical solution to an unfriendly 5-speed gearbox. My Vitesse used to have a truly nasty gearbox. It baulked at will and was notchy to a fault. In fact it was very, very hard work. This was my last resort.

• During a routine gearbox oil level check, I noticed how dirty the lubricant had become so it was obvious it had to be flushed and changed. It had the recommended ATF which Rover had been forced to specify, because the gearbox was unreliable when filled with conventional lubricant.

• By coincidence, I had been told by an Ex-Mobil employee that Mobil 1 or Castrol RS at 0W40 or 5W40 viscosity were considered by the trade to be a better replacement than ATF in the Rover 5 speed box and gave a much improved performance.

• With the car on axle stands and the back wheels off the ground I drained the box and re-filled it with a flushing mixture of 2:1 white spirit and ATF (I did say radical and it was a last resort!).

• With the engine running at idle speed only, I put the car through all the gears and let the drive train run off-load for 5 to 10 minutes.

• Upon draining the flushing mixture I was amazed at the filthy color and state of the drained fluid. It was as black as ebony with lots of sediment!

• I repeated the above with a clean batch of mixture to flush out the residues. One can imagine the washing machine action inside the box allowed the solvent component to reach into every recess.

• The box was then refilled with 5W40 "Castrol RS" (0W40 "Mobil 1" is virtually the same and I have subsequently used both with no discernable difference).

• I then added a recommended dose of Molyslip Gearbox Treatment. This stuff comes in a tube-like applicator and is available from Halfords, etc.

• The transformation was miraculous. It has run for over 12 years without any of the original symptoms and is a total pleasure to use.

• The oil has been replaced thrice in that period with Mobil 1 or Castrol RS and the same Molyslip gearbox additive each time.

There is more gearbox stuff here:

http://www.vintagemodelairplane.com/pag ... box01.html

[ian.stewart]

Gearbox antifriction addatives, sort of defeat the object of syncromesh, by reducing the friction, the cones do not grip as well, and do not speed up the gears effectivly, although its not allways apparent, and the syncros have to work hard to give smooth changes, after a while the syncros die,
A good oil is allways a good move

[sidecar]

Gearbox antifriction addatives, sort of defeat the object of syncromesh, by reducing the friction, the cones do not grip as well, and do not speed up the gears effectivly, although its not allways apparent, and the syncros have to work hard to give smooth changes, after a while the syncros die,
A good oil is allways a good move

The Redline website mentions this and has some graphs and other "clever stuff" that shows how the wrong oil will damage the cones.

Before I knew any better I bunged in dexron III into my box, every single gear change, hot or cold was bad! I posted up about this a someone who knew his stuff said that III was far too slippery and would not work!

Pete

[tetlow]

Thanks Gents

One thought though. after 500 miles should the oil be like new?

[ramon alban]

Gearbox antifriction addatives, sort of defeat the object of syncromesh, by reducing the friction, the cones do not grip as well, and do not speed up the gears effectivly, although its not allways apparent, and the syncros have to work hard to give smooth changes, after a while the syncros die,

That seems like a valid observation. The treatment used was for gearboxes, so perhaps the formulation was appropriate to the need. Your comments do not strictly rule the treatment out.

A good oil is always a good move

To Tetlow, Give the Mobil1 or Castrol RS lube a try. All I can say is, apart from the cost, what is there to lose? And no, your 500 or was it 5000 miles usage is not working and perhaps it will not need the system flushing unless you think its dirty enough when its drained.

One thing about the flush is that its amazingly effective at clearing out the dross.

It really all depends upon forum members no guarantee opinions and which one you fancy.

[tetlow]

Cheers Ramon.

I was thinking of draining the Redline, flushing and trying your suggestion as even when the oil is warm the change is poor.

I would save the Redline and put it back in if needed.

The box has only done 500 miles since the rebuild and new oil.

Dave

[stevieturbo]

I know I tried Mobil in mine....but its that long ago, I really cant remember what it was like before, or after.


I know that more recently, I was told when cleaning a box...use cheap engine oil to flush out any previous oil....just a brief drive til the box is warm.


In my T56, I furst used Fuchs ATF4000...which worked very well...its fairly cheap, so could be worth a shot if sticking with a ATF

In other manual boxes, Ive had good success with Castrol Syntrax. It certainly works wonders in Subaru boxes, so again....it would be worth a try if wanting to try a gear oil.

I know I tried one of the Redline Shockproof stuff in my Supra box...TBH, I thought it was crap, shift was terrible hot and cold. I ended up using Syntrax in it.

[ramon alban]

I was thinking of draining the Redline, flushing and trying your suggestion as even when the oil is warm the change is poor.

Dave, further to my prior comments, I would add the following.

Very often, answers to these type of questions are often qualified by riders such as: "someone told me that", "My mate says", "In my opinion", "I read somewhere", "I heard on the tele", etc.

In this case let me reiterate the geneology of my recommendation. It happened to me, its a first hand account, I dont sell anything related, and the only reason I would throw caution on my advice is because, if someone wanted to blame me for damaging their gearbox, I would take the defensive attitude that " you try this at your own risk, as I did"

I was given lubrication advice by a Mobil employee who was also an SD1 owner.

My Twin Plenum Vitesse gearbox was then about 8/9 years old and was virtually impossible to use

It was lubed with ATF since it came out of the showroom

I was prepared to sacrifice it if necessary or have it rebuilt or buy a replacement.

The flushing process as described was low stress, benign and very effective judging by the cleanliness of the fluid following second flush.

The oil used is amazingly thin if not as watery as ATF.

The gearbox treatment was purchased from Halfords and contains molybdemum disulphide.

The box was gradually transformed into being super friendly after about 50 miles.

That was in 1996/7 and in the intervening years the car has done about 40000 miles without any gearbox issues at all.

The oil has been replaced three times with the additive also, each time the box was flushed, but it seemed hardly worth the effort as there appeared to be no significant silt inside.

In the SD1 community, there are several other owners who tried the process and they all had varying degrees of improvement.

Cheers

Ramon

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