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I've finally figured out that my 1975 XJ6C has a BW66 transmission probably changed out by the PO. Not a BW65. So... my parts manual only shows a BW65 as it's a Series II parts manual. It shows a speedometer gear in the tailshaft that requires a 13 teeth gear for my 3.31 rear end. I counted the teeth on my gear and it is 20! Anybody know what my options are? There is a right angle gear mechanism that is a 1:1 ratio - I counted it also.
Any half decent Transmission Parts Supplier would have those drive gears, and memory?????, is BW 35 did come with many, many gears, as that trans was used in tooooooo many different cars during its life.
Same basic trans as the 65 and 66. BW never really messed with a known working unit, basically if it aint broke, dont mess with it.
Any half decent Transmission Parts Supplier would have those drive gears,
Hopefully the BW gears are the same as used in some of the more popular and common transmissions seen in the 'States....which would make it a click-to-buy proposition.
If they're unique to BW....a bit of searching might be required.
I've finally figured out that my 1975 XJ6C has a BW66 transmission probably changed out by the PO. Not a BW65. So... my parts manual only shows a BW65 as it's a Series II parts manual. It shows a speedometer gear in the tailshaft that requires a 13 teeth gear for my 3.31 rear end. I counted the teeth on my gear and it is 20! Anybody know what my options are?
Besides the drive gear on the tailshaft there's also the driven gear that slides thru the transmission case. How many teeth on it? I wonder if it came from the replacement trans?
Anyhow you might be able to change only the driven gear....which is very easy. The are many online 'speedo gear calculators' which will do the math for you. But, the difference between 13 teeth and 20 teeth is large enough that a driven gear with the right number of teeth to compensate might not be available.
There is a right angle gear mechanism that is a 1:1 ratio - I counted it also.
You can buy those drives in a variety of ratios to speed-up or slow-down the speedometer. First, though, you'd need to determine your amount of speedo error as a percentage and work from there.
Thank you. I'll now start referring to the drive and driven gear properly. Since this is a BW66 and my parts manual only covers a BW65 - Can someone put a pic of the BW66 out of their Series III parts manual? Specifically the page where it shows the different DRIVEN gears for the different rear end ratios. I need to see if there is such a thing as a 20 tooth driven gear (and what rear end ratio does it go to) and a driven gear that matches a 3.31 rear end.
Okay, I'm still confused. That link helped me a lot in finding out that there is indeed a 20 tooth driven gear for a 2:88 rear end. Again mine is 3.31. I see part numbers for all the different driven gears but not different part numbers for the driving gear???? Can it possibly be that the one driv
ing gear is the same for ALL the driven gears????
Okay, I'm still confused. That link helped me a lot in finding out that there is indeed a 20 tooth driven gear for a 2:88 rear end. Again mine is 3.31. I see part numbers for all the different driven gears but not different part numbers for the driving gear???? Can it possibly be that the one driv
ing gear is the same for ALL the driven gears????
Drive gear for the 2.88 rear end is EAC4414. All other rear end ratios used the C43875 drive gear. No mention of how many teeth but that info is probably out there to be found with a little digging
I found a couple of pics out in EBay of a C43875 in Europe that the Seller ended. Here are the pics, but I'll be darned if I can find any page in any Jaguar Series III parts manual showing that part???
Only having a parts manual for a Series II which had BW65's, I don't have access to any Series III parts manual except online. And this is what I show for Group D 1E 7L. Maybe I should just start research a ratio adapter (with proper reduction).
Speedometer/Odometer over reading-reading high
