shock proof gear oil

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shock proof gear oil
Bernhard said:
And an almighty big fine from the Revenues and Customs if you get caught?
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They have always taken that seriously in the UK.

Don’t run your diesel Norton on the red stuff!
 
jseng1 said:
Dirt track bikes accelerate to top gear, slide around the track and never shift again until the race is over. So I don't think they are a good example as a test for ATF in a constantly shifting street bike or road racer because once you reach top gear the gears are freewheeling and the only stress is on the shafts and bearings.

I remember rebuilding a sportster gearbox and the customer was very nervous about blowing it up again. The word was that they were "fragile" when subjected to a tuned motor.
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Which model year was it, Jim? I have obtained a 2003 model Sportster cluster which looks rather robust. If I am not mistaken, Kenny Dreer used it in the 951 prototype. It looks remarkably similar.

With reference to ATF oil and its ability to prevent gear fretting, a definitive answer hasn't been presented, has it? Or did I miss something? I would like to add to the above that any kind of racing application which involves frequent rebuilds (as do most racing engines and transmissions) will hardly deliver a proof, unless the life of a certain pair of gear wheels is recorded minutiously, similar to an aircraft inspection scheme. I doubt even factory teams make such records, unless it's development work prior to launching a new model. In a racing workshop, any sign of wear detected and the pair of gears will be replaced, as a matter of profilactic practice.

Was fretting detected at the time the Commando was manufactured? I doubt long distance testing revealed it. There are articles on gearbox rebuilds in the magazines, e.g, Classic Mechanics. In the article published Febr/March 1987 Mick Hemmings points at gear fretting as a possible damage to gear wheels and recommends replacement. This was 10+ years after manufacture.

-Knut
 
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I'm assuming that the higher the film strength the less gear wear. So a film strength comparison would be a good place to start. Thick oil would seem to provide more film strength and that's generally what I hear and read about but there is so much BS on the net with each brand bragging their superiority and synthetic advantages that I haven't found an unbiased comparison yet - so its still up for argument.

The reason people use ATF in racing is for some small friction savings because of the low viscosity.

My impression is that the gears run quieter with the heavy shock oil. This is especially apparent in my 4WD Willys truck which has gears everywhere (tranny, transfer case, overdrive, PTO winch, ft & rear differentials).

Knut
The hopped up sportsters I've known about had cartridge gearboxes and were questionable. Rumors I heard from the shops and the riders was that the stock parts were marginally reliable in high performance motors. I've seen the broken teeth. This was in the 1980 - 1990s. They may be stronger now.
 
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The 4 speed sportster box fitted up until the early '90s was known to be fragile, 5 speeds fitted since seem to be better though I have not been playing in that field lately.
 
Although I find it amusing to read about Harleys and other brands of tractors, I might have something about oils.
The TTI gearbox I use in my Manx came with a paper, stating recommended oils. Both where GL-5. Checking the data sheet one the one I use, it said that it did not harm any metal used in gearboxes. TTI also strongly advised:
Don't use shock proof oil.
 
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Mike40M said:
Although I find it amusing to read about Harleys and other brands of tractors, I might have something about oils.
The TTI gearbox I use in my Manx came with a paper, stating recommended oils. Both where GL-5. Checking the data sheet one the one I use, it said that it did not harm any metal used in gearboxes. TTI also strongly advised:
Don't use shock proof oil.
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Did they say why? Conflicting opinions on this.
 
This has been mentioned before about TTI boxes, a tech at TTI told me that any gearbox that came back to them for repair/service that had been using the shock proof oils took so long to remove the remnants of the oil and cleaning up the housings was such a messy business they recommended not using it!
Not an urban myth
 
From TTI
  • 3) Use the recommended oil.
Using the wrong oil can wear out bearings and gears faster than usual, resulting in strange noises and stiff shifting. Eventually the gearbox could seize up resulting in major damage. TTI sequential race gearbox users should make sure they are running Motul Nismo Competition Oil 2189E 75W-140m , or Castrol Axle AP 85W140 or similar spec oil. As outlined in the TTI car gearbox owners’ manual DO NOT use shock proof oils as the oil does not flow through the bearings.
 
Hortons Norton said:
From TTI
  • 3) Use the recommended oil.
Using the wrong oil can wear out bearings and gears faster than usual, resulting in strange noises and stiff shifting. Eventually the gearbox could seize up resulting in major damage. TTI sequential race gearbox users should make sure they are running Motul Nismo Competition Oil 2189E 75W-140m , or Castrol Axle AP 85W140 or similar spec oil. As outlined in the TTI car gearbox owners’ manual DO NOT use shock proof oils as the oil does not flow through the bearings.
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That's why I've been mixing it - the majority of it being 75-90 wt mineral or synth gear oil. Treat it as an additive and it flows through the bearings no problem.
 
But Redline SPH is 75W-250. Doesn't it actually flow as a 75W when cold? Honest question....this thread has me ready to run out to the garage and drain the gearbox....!
 
Cant understand the claim Shockproof doesn't pass through bearings. Its certainly thin and flows enough. Any doubt just pour some on a spare bearing on your shelf.
 
I have heard similar about bushings, but not bearings. Maybe its flow properties in use are different than pouring it over a bearing on your bench?

comnoz said: ↑
I only used Redline Shockproof for a year. I don't remember what weight it was or even if there were different weights at that time. I would guess it was 15 years ago.
It did stop any migration of the oil down the input shaft, but when I found the bushing was loose and pulled it apart I found the outer bushings were dry and the shaft was blue from heat. I went back to ATF and have stayed with it since.
 
What I get from heavy shock proof is that the gears run quieter. For me this is an indication that there is less metal to metal contact and hopefully - longer gear life.

There are a few rumors that heavy shock proof may not get through the tighter clearances of the bronze bushings (ball bearings are not a problem) and this is why I started this thread with the suggestion to only mix heavy shock proof with regular type (or synthetic) gear oil - in other words to use it as an additive. This is the way I run it in my own bike. Presently I'm trying approx 30% or less of 75-140 shock proof in my gear oil. You want the best of both worlds - an oil with a shock proof coating that cushions the gear contact (gears run quieter), but not so thick as to prevent oil to the bronze bushings.

Some people suggest ATF but I'm not comfortable with the lightweight aspect and references suggesting the lower film strength of extremely thin 10 wt oil in the gearbox.
 
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jseng1 said:
I remember rebuilding a sportster gearbox and the customer was very nervous about blowing it up again. The word was that they were "fragile" when subjected to a tuned motor.
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possm said:
The 4 speed sportster box fitted up until the early '90s was known to be fragile, 5 speeds fitted since seem to be better though I have not been playing in that field lately.
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The comments about the old Sportster 4 speed gear boxes being fragile is pure BS. Look one over carefully - the bearings, the shaft sizes, the gear width, gear material, the negative rake on the engagement dawgs, etc, and you’d realize that this tranny is way out there on the robust end of the gearbox design spectrum. They are a really tough tranny. Also be aware that people abused the shit out of them since the 1950’s and that they had lots of hands on them over the decades that were 100% clueless regarding reassembly and rebuilding. Oh you mean some of these shims were supposed to be in there when I reassembled it? I wonder what these offset shifter forks were for, my box didn’t seem to need them? It doesn’t really shift that well on the bench, but I’m sure after I run it awhile it will get better. And you wonder why some of these blew up?
 
WZ507 said:
The comments about the old Sportster 4 speed gear boxes being fragile is pure BS.
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Perhaps fragile isn't the correct term. My recollection is that when AMF owned Harley the quality went down the tubes. A friend had a new '76 Sportster Centennial edition and had nothing but trouble with his gearbox.
 
WZ507 said:
The comments about the old Sportster 4 speed gear boxes being fragile is pure BS. Look one over carefully - the bearings, the shaft sizes, the gear width, gear material, the negative rake on the engagement dawgs, etc, and you’d realize that this tranny is way out there on the robust end of the gearbox design spectrum. They are a really tough tranny. Also be aware that people abused the shit out of them since the 1950’s and that they had lots of hands on them over the decades that were 100% clueless regarding reassembly and rebuilding. Oh you mean some of these shims were supposed to be in there when I reassembled it? I wonder what these offset shifter forks were for, my box didn’t seem to need them? It doesn’t really shift that well on the bench, but I’m sure after I run it awhile it will get better. And you wonder why some of these blew up?
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Absolutely and 50s bikes had the weakest cases which improved into the 70s - 80s. The speedo drive was the weak point, eventually shedding a tooth, jamming the gears, separating the shafts and blowing the bottom corner of the trans case.
My own 72 with 25k is a little heavy, but the box works great.
 
I have to back you up on the sporty gearbox being stout..... My '77 CR was taken above and beyond never failing, but I couldn't claim the same for the motor I blew in a most spectacular cloud of dust and smoke. .50" over and good as new with 4 valves & 2 pistons.
 
alan hodge said:
here it is mom told me great grandfather bought it new in '39 for $1000 I found it in a shed where it had sat for 40+years worked on it for a year to get going again it's our 5000lb family heirloom has original dataplate serial # indicates only 150 more of this model made after this one
shock proof gear oil

shock proof gear oil
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Is this the F12 or F20?? A couple of years back I replaced a radiator in a F20 for a friends like yours with tricycle front end....... what a B****** Of a job it was!!!!
 
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