S/C drops on a road car

[Dan Tweed grey]

Yes, got them on my phone and have no idea how to post a link.
I could possibly watsapp them?

[Dan Tweed grey]

https://photos.app.goo.gl/BbTCBTeoiH9zYaZH9

[Dan Tweed grey]

Did that link work?

['S'-type]

There are quite a lot of youtube videos on this. Both in car and from outside. One on there (rolling road) sounds like a bloody siren.

[Andrew1967]

Did that link work?

Yes, it did Dan - thanks for that

Sounds great to me

[Andrew1967]

There are quite a lot of youtube videos on this. Both in car and from outside. One on there (rolling road) sounds like a bloody siren.

I have watched a few on YouTube, but wondered if anyone on here who has expressed a preference or advised against had any to share

Think I've watched the rolling road one

Just wondering whether to use my straight cut drops and the straight cut gears ?

Will only be a purely fun, once every so often drive. Certainly not a daily driver.

['S'-type]

There are quite a lot of youtube videos on this. Both in car and from outside. One on there (rolling road) sounds like a bloody siren.

I have watched a few on YouTube, but wondered if anyone on here who has expressed a preference or advised against had any to share

Think I've watched the rolling road one

Just wondering whether to use my straight cut drops and the straight cut gears ?

Will only be a purely fun, once every so often drive. Certainly not a daily driver.

Quite a few of the older (wiser?) heads on The Mini Forum say it's a no no on a road car and especially a daily driver. Most people who use the car a lot on the road end up taking them out. Bleeding ear syndrome. But for racing and a bit of occasional posing not a problem. Depending on quality, it's the drop gears that make more noise than the straight cut box.

[Spider]

I'm not sure how one would go about aligning the gears.

I'm pretty sure the Drop Gears tend to be quite loud for a few reasons apart from them being straight cut;-

The Transfer Housing is thin and not as well ribbed / supported as the gearbox case and so tends to accentuate the sound,
Unlike the Gears in the Gearbox, these don't run in an oil bath but as splash fed, so there's much less oil to drown out the noise,
But the big one next to the gear tooth design is the usual poor alignment between the Gearbox Case and the Transfer Housing

It's also down to the actual tooth design and the contact ratio that can be achieved. Most straight cuts are around 0.9 to 1.0, but with careful design, that can be as high as 1.1:1 (that's the limit for straight cuts) though, they are usually more expensive to cut this way. Helicals on the other hand (of the type in our drop gears) are (from memory) 2.2:1 for the early types and 2.5:1 for the A+ types.

All the same, as I mentioned earlier, this REM process I haven't tried and has my interest. Just one further question here is how's the long term wear on these gears ? I maybe misunderstanding the process, but with the chrome like finish that's left on them, I wonder how they hold oil on the teeth ? If you read up on the finish specs for many steel and non-ferrous parts than are not pressure fed with a lubricant, they require a certain minimum surface 'roughness' in order to hold lubricant and if the surface is too smooth (polished) then the parts can fail from inadequate lubrication. There may well be something in the REM Processes that overcomes or addresses this ??

[CooperTune]

Sorry I was not thinking about aligning the drops, of course the alignment between case and clutch housing can be checked and adjusted with some machine work. All my former Vintage race cars have moved on to new owners and are still taking part in Vintage. I have a couple sets in street cars that may never come apart. I know of a set in service for 13 years racing. I'll give a call to the west coast Monday and ask when was it last freshened? Steve (CTR)

[ivor badger 3]

To put the noise in perspective. worked on a raly car with straight cut gears, box and drop. Thcar also had a 45 Weber, no air filter. Driving on the road, you heard the box before the Weber. Could pass any rally stationary noise check.

[Spider]

Sorry I was not thinking about aligning the drops, of course the alignment between case and clutch housing can be checked and adjusted with some machine work. All my former Vintage race cars have moved on to new owners and are still taking part in Vintage. I have a couple sets in street cars that may never come apart. I know of a set in service for 13 years racing. I'll give a call to the west coast Monday and ask when was it last freshened? Steve (CTR)

Clearly then, when treated, they do seem to last OK then.

I've been aligning the Transfer Case to Gearbox Cases for a few years now (as well as other 'rework') and found this alone has paid good dividends. While I've only been checking / correcting late cases (which are shocking), I'm sure that given the way these parts were mass produced and what they were trying to achieve, few would be accurate and I doubt any, spot on. I'm sure in their initial design some allowances were made for these misalignments and so by aligning them not only further quieten them down, but I'm sure will also increases their life. One point of frustration though is that I've found all the shafts that run needle rollers are undersize, presumably to allow for mass production tolerances and also this misalignment.