04 Sportster 883 gearbox Clunk.

[Nomad]

My 1200 goes clunk in first and Crash into second! and its only done 2800 miles. I wonder if the forwards linkage is to blame for the second crrraaaachhhh! but I dont want to fiddle with it in case they all end up going crashcrunchmangle!

[BlackEagleS]

i think it has to be accepted that the harley gearbox is noisy when going into some gears but for me its the degree - i might as well have a tin with a few big spanners in it and just drop it on the road when i select 1st at the lights/junction cos it couldnt make any more noise.
anyway im not one to let such things go uninvestigated but i didnt know what other 'similar' to hd syn3 oils (which i think is made by a company called Sunoco) were available and i had it in mind to up the grade to sae75w-90 in the hope of reducing the noise.
so i wrote to 4 oil companies (rock, mobil, castrol and comma) to see what they had to offer. rock, who have been in car and bike competition/racing for some 80 years, replied within 30 min and have synthesis 4 racing, gardian 20w-50 and strata 20w-50. mobil, castrol and comma replied the next day and have mobil 1 racing 4t, act7evo 20w-50 and sonic 20w-50 respectively but the comma one has a 'small' amount of friction modifiers. if anyone has insomnia then All About Motor Oil tells the oil story. ive decided to go the rock oil route - they all meet JASO MA, API SL and ACEA A3 Industry approvals/grades and my local v-twin expert has been using it in all his serviced machines for years.
all the products are different prices so anyone interested will have to make their own judgement.
oh.. and i feel a bit stupid but i asked about using sae 75w-90 but it seems oils are rated by different viscosity indexes (vi) and sae 75w-90 is about the same as sae 10w-40!!! cos they are on different vis. im told that sae 20w-50 is about as high an sae as you can get in its vi.

[HOG maniac]

Interesting. I will continue to use my 75W90 until someone has a better recommendation.

[BlackEagleS]

at least it only a gl4 rating so doesnt have high concentration of sulfurized additives used in gl5 so it wont eat your bushes.

[HOG maniac]

Please explain. Is my GL5 eating my bike ?

[BlackEagleS]

taken from tundra solutions.com

GL-5 gear oils are for gears like differentials where the pinion is below the centerline of the ring gear. There is much sliding on the gear teeth, and the oil has to be blended for that. These are called hypoid gears. A gearbox without hypoid gears, like a transmission, does not need this particular additive package in the oil. GL-4 gear oil works well. Some GL-5 oils used a sulfur based additive to make them GL-5, and the sulfur would damage yellow metals...brass, bronze, & copper...in the transmission. Many modern GL-5 gear oils do not have the sulfur in them and are labeled for both GL-4 and GL-5 applications.

i do not wish to alarm you and i expect im wrong but i see comma make two grades of sx75w-90, a gl4 and a gl5 so im assuming the gl5 will have the additives otherwise there is no point in producing both grades. i was rather assuming the picture you used was just for illustration but you may think it worthwile to check the grading. i have emailed comma to ask them.

[HOG maniac]

Interesting. I checked and luckily have been using the GL4 grade. I would be interested to see if they do add the sulphur and if they offer any warnings on the can.

[BlackEagleS]

Originally Posted by HOG maniac

Interesting. I checked and luckily have been using the GL4 grade. I would be interested to see if they do add the sulphur and if they offer any warnings on the can.

hog. needless to say the company never replied to the question, read into that what you will. ive now changed to rock strata 20w-50 (seems it had that 'workshop+' stuff in it which i think is 15W-40 and used by the harley dealer it was last serviced with) so lets see if it is any good, certainly dont seem to get the gear grating but plenty of clunk still!! but ill call it a positive gear change sound.