6 speed gearbox, 2005

[timb2117]

Ok bit of a story, I'm in QLD Australia in next few months want ot refurb' my gearbox, Caterham own 6 speed; parts & reliable help long distance?

Ideally I would like to email a specialist the faults, (precis: sticky when going out of 4,5,6 particularly when hot, and a bugger to get into 2nd, feels like its in then release clutch hear noise, but no engagement dip clutch again push lever harder and its clunky but in) I have changed the saddle on selector and oils but very little improvement, figure at 15 years old she needs a rebuild.

Who can I go to for parts and advice so that when the box of stuff arrives A. its correct for the box. B. It cures the faults as per my description? Ideally I want minimal down time for the car so these points are fairly key.

As a side issue is this box a ford sierra case with Caterham internals? I hate to be sceptical but most makers don't build from scratch ground up.

 

thanks folks. 

[Wrightpayne]

A lot of the parts are carried over from the Ford type 9, 5 speed.

I would find yourself a local type 9 expert / specialist then get in touch with Road and Race Transmissions for advice / parts.

https://www.rrtransmissions.com/

[elie boone]

It has all the symptoms that the wrong oil is in the box, probably GL5, what you need is GL4 oil. I would drain the oil and put new GL 4 oil in and see what the result is.

[David_Long]

Yes, I would try some Redline MTL (GL4) in it before taking it to bits. It's yellow metal synchro (old technology), and modern slippy oils just aren't very good to get the synchro working well.

Edit to add:

Found this bumf on  MTL which backs my own experience. I found using it all the time was not a great idea as wear is higher, but every now and then helped sort out synchro problems. 

''RED LINE MTL and MT-90 are designed to provide excellent protection and improved shiftability for manual transmissions and transaxles. MTL and MT-90 have cured the problem of hard shifting in numerous transmissions which have notoriously difficult shifting.
The secret to their success is two-fold. First, they have the appropriate coefficient of friction for most manual transmission synchronizers. Many gear oils, engine oils, and ATFs are too slippery for proper synchro engagement. Secondly, the viscosity characteristics of MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 75W, almost a 70W, at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. ''

[Mcalvert]

Hi Tim - not directly relevant, but there's sone information about the development of the 6 speed box and what was carried over from the Type 9 in the Lowflying archive here:

Otherwise, this is another thumbs up for Road and Race Transmissions  

 

[7 wonders of the world]

The person to speak to is steve perks at sp components he is afaik the only person who has re engineered several pieces for the 6 speed box to overcome at lot of the gremlins including those you mention. Mosst other repaierers simply fit new parts and the do the same thing again down the road.

[ScottR400D]

#4 Not only that but the use of a GL5 can damage the yellow metal parts in the gearbox. 

The Difference between GL-4 and GL-5 Gear Oils by Richard Widman:

“The problems arise when we try to use the same product in the transmission that we use in the differential. Many people have called oil companies and been told by the “Techs” that answer their questions that their oils have buffered sulfur and therefore are not corrosive to yellow metals, so their GL-5 oils can be used with brass components. While that answer is totally correct, it does not address the question asked: Can I use your GL-5 in my synchromesh transmission?
Let’s take a look at the API GL-5 rating. It is a rating for EP (Extreme Pressure) protection. The higher the EP protection, the higher the GL category. In the mid 60's, Ford needed better protection in their pickup trucks and GM developed the front wheel drive Oldsmobile Toronado that had a differential with a very high angle of contact for power transmission to the wheels so a higher category was developed (later to be called GL-6) to offer the protection needed. This level of protection can still be claimed, but can no longer be tested since the Toronado rig used to test it is no longer available. (Note: The 1966 and 1967 Toronados had sun gears between the axle shafts instead of spyder gears and a very high offset, while suffering from the high temperatures of the engine compartment and very high pressures.) This is why you will frequently see GL-6 listed as “obsolete”. The test is obsolete, not the car or its needs. Many other high performance cars continue to spec this level of EP performance.
In normal operation, the sulfur/phosphorous additive forms a black sacrificial coating on the gears and anything it touches with a little pressure and temperature. As the gears turn, instead of wearing, the sacrificial coating of additives is peeled off or worn off. This is normal and acceptable in all steel gears. But when one or more of the surfaces is brass or another soft metal, the sacrificial coating is stronger
The Difference between GL-4 and GL-5 gear oils 1 of 13
than the base metal, and instead of just peeling off, it takes with it a few microns of brass that it is bound to.
A traditional GL-4 gear oil of any given viscosity has about 1⁄2 of the level of sulfur/phosphorous additive that would be in the GL-5 product, so the bond is not as strong, and therefore can be peeled off without peeling a layer of brass (or less brass). This means that the GL-4 product provides a little less extreme pressure protection, so in the differential of a high-powered car, it would not be the ideal product in the differential. To understand this need we should be aware of the fact that the differential is where the final torque is applied to the wheels (in most applications).
But in the transmission, we should consider two factors:
• Due to the fact that the differential applies the final torque, normally we do not need the full EP
protection in the transmission where less torque (about 30%) is applied.
• We need to be able to break the EP protection to stop the spinning of the gears long enough to
mesh them or synchronize them.
When we use a GL-5 product in a transmission that requires GL-4, we normally find 2 to 4 times as much copper in the used oil as we would with a GL-4 product (with used oil analysis). Eventually the synchronizers wear to the point that they no longer make contact with the other half of the cone, bottoming out before stopping the opposing gear”

[Wrightpayne]

I doubt very much Mr Perks will tell someone on the other side of the world his trade secrets concerning the 6 speed box. He explained at length to me how he arrived at the bore honing size for second to stop it seizing but also said only he and his machine shop know the information.

Besides the OP would never afford the phone costs for the quick chat with Steve :-)

I will not use SPC again. I posted about my 6 speed problems some time ago, after a rebuild, which could have been catastrophic.

[timb2117]

Brilliant guys lots to go on thankyou! Yes redline MTL GL4 is in it - this was my last try and it did improve 2nd very slightly but that's it.

Many thanks for the background on the Ford type 9 Mr Payne I have used one of these boxes before - about a lifetime ago :) it was a strong box and hopefully there will be a deal more info available now you have confirmed - torque settings etc for assembly/ disassembly and I can hunt on line in earnest..

Just guesses guys, the 2nd gear issue, worn synchro or worn selector fork....Wild guesses accepted (I'll replace both anyway)

[elie boone]

To improve cold shift u can use ATF oil but it wouldn't change the other problems.

[timb2117]

Ahhh ok done some more digging based on your good advice, essentially 2nd has improved when hot with the MTL, but I have still made a faux pas, its hot here like real hot all the time, the MT90 should give me another gain so I will try that.

- essentially the longer I can prolong the inevitable gearbox rebuild the happier my wife will be :)! Would be nice if it could get past the sticky to get out of 6th etc hassle, as I am a bit envious of the descriptions here of "like a rifle bolt" shift, when I have to give it a solid nudge just to exit the gears. Will update when the 90 is in and road tested.

Thanks agian all will contact specialists too and start forming a plan for the rebuild.

[aerobod - near CYYC]

There is also the option of MT85. I find that it strikes the best balance for me for both hard use and operation before fully warm. I started with MTL, then went to MT90, then settled on MT85.

[7 wonders of the world]

One thing to check to help the shft is the condition of the rose joint under the gear lever, and what position your gear lever is in, theres a std which is already 'quick' and 'extra quick'

I tried the later, which could be fine for track but found it lacked the finesse of the std position needing far more force.

Very simple to swop either way though, just a circlip once its out.

 

[timb2117]

Ahh ok thanks 7 wonders, will do that I did replace the saddle early on but did not note any adjustment and it makes sense that short fast throw would be my enemy at the moment, will dig into it, gonna be a long haul :)

& aerobod turns out that the only dude here with the mt90 now expects a 10 day delay for restock, drat. but as its ordered I will tramp your path....

[Wrightpayne]

Just a thought - How prevalent are the type 9 5sp boxes where you are? Could fit one temporarily for a season while the 6 speed is 'in repair'? 

[7 wonders of the world]

There must be plenty of places who look after older V8 Fords with the top loaders etc, if they are proficient in these then the 5 and 6 speed aren't a million miles away in technology.

If they can strip it and contact Steve Perks he can ship the parts out that are required.

[John Vine]

Re #13:

Very simple to swop either way though, just a circlip once its out.

There's a guide here that may help.

JV

[timb2117]

Thanks guys, V.few people even though I live in  suburb that is literally peppered with car trades, I have contacted a specialist in Sydney about a rebuild kit that they stock and they had literally zero idea in spite of photos, detailed descriptions etc, this application stopped them dead.

John that's great I will use the guide and strip rebuild the link again, it certainly heads off  a couple of hassles I had when I changed just the saddle clip, wish I had that guide then I'd have checked the setting....

I'll choose a quiet time and get it all expressed from Mr Perks & road and race. Exactly what I was after from the forum many thanks as always the devil is the details.....