Is anyone using this combo and has replaced the speedo drive gears to make the speedo read correctly? Any part numbers or info you could provide would be appreciated. Since the 3.90 is mainly a Cressida gear and very few of those came with a W58, Im wondering how hard this is going to be to get working properly.
SupraWes
Wes,
I changed my 4:30 gear out for a 3:90 gear earlier this year and I simply had to change the speedo cable driven gear. The trans-drive/speedo-driven gear combination for the 4:30 was 10/35 teeth respectively. The combination for the 3:90 gear is 10/31. If you are not already aware, the tooth count for the gear combos are indicated on the face of the driven gear. Have fun Wes!
Regards,
Carlos
I changed my 4:30 gear out for a 3:90 gear earlier this year and I simply had to change the speedo cable driven gear. The trans-drive/speedo-driven gear combination for the 4:30 was 10/35 teeth respectively. The combination for the 3:90 gear is 10/31. If you are not already aware, the tooth count for the gear combos are indicated on the face of the driven gear. Have fun Wes!
Regards,
Carlos
Interesting, when I asked my local Toyota parts place what teeth I could get, they only said 32, 33 and 34 teeth.Carlos Brown said:
Do you have the part numbers for the 31 and 35 teeth? Do they do a 36 tooth gear?
FYI
4.10 gear is 10/33
3.73 gear is 11/33
You can also use 11/35 for a 3.9 gearset, but it will read 0.5% out compared to 10/31
PeeWee,
I am tearing through all of my old receipts in an attempt to locate that part number. No luck just yet, but I will keep you informed. If memory serves me correct, I believe I ordered a driven gear for a 1987 Cressida w/3:90 and W58. I will post when I come across the info...
Regards,
Carlos
I am tearing through all of my old receipts in an attempt to locate that part number. No luck just yet, but I will keep you informed. If memory serves me correct, I believe I ordered a driven gear for a 1987 Cressida w/3:90 and W58. I will post when I come across the info...
Regards,
Carlos
yeah, the parts guys dont think to look for other cars. just tell you waht was on the mkii stock.
william
william
In Aus the Cressida never came as manual, and the Supra's all had the same diffs.
So we have very little listed on the Toyota computers
If I have the part number though, I can get anything providing its in stock somewhere.
So we have very little listed on the Toyota computers
If I have the part number though, I can get anything providing its in stock somewhere.
Hey, maybe you guys know. I'm trying to get a Fidanza flywheel for my 1G, which from what I understand, has a "W" series tranny. Does anyone know any model of car I can reference for the Fidanza guy to get the right flywheel?
Oh man, THANK YOU PeeWee. I just swapped for a 3.73 rear end for the turbo but the person I'm swapping with didn't have the right speedo gear. You just made my hunt for the speedo gear much easier (I hope). Assuming that the local Toyota parts guys will know what I'm asking for...Peewee said:
Have just got to love how well the search feature works.
Leslie
Well Gentlemen,
I posted a reply here earlier in the day on Sunday, February 6th, only to check back later in the day and find it gone... The post was in response to the question "How to determine the proper speedo gear combination," which had been posted by Leslie (that post also disappeared).
Well, the first portion of the response is for informational purposes only - unless you are bored one night and feel like doing some mathematical computations. The primary variables utilized in speedo gear determination is speedo and tire revolutions per mile (RP/Mile), along with tire height and gear ratio. The computation matches 1000 speedo RP/mile to (x) tire RP/Mile. This ratio of course factors in tire height and axle gear ratios. It goes something like this...
Speedo Gear Calculator
1.) Determine Tire Diameter ( 225 x 60 x 14) = 24.63"
2.) Multiply Tire Dia. by pi ( 24.63 x 3.1416 ) = 77.38 tire circumference
3.) Divide one (1) mile into inches or multiply yards by inches (1,760 yards x 36 inches ) 63,360
4.) Divide 63,360 by 77.37 ( 63,360 / 77.38 ) = 818.8 RP/Mile of tire
5.) Multiply tire RP/Mile by Axle Ratio to determine driveshaft RP/Mile ( 818.8 x 4.30 ) = 3,521
6.) Divide by 1000 speedo RP/Mile (3,521 / 1000) = 3.521 (Round this number to 3.5 - this is the ratio you want to achieve).
You will now need to research the available gear ratios for your tranny and determine which combination will work best. My 86 Supra came with a 4.30 rear gear and a 35/10=3.5 speedo gear set. When I went to the 3.90 rear gear I chose the best available speedo set which was the 31/10=3.10. After doing the calculations I found myself at an actual ratio of 3.19, which ends up at a 2.8% error (3.10 / 3.19) x 100 = 97.2 or 2.8%. After correcting for my taller tires (25.1") I recalculate a speedo error of only 1.0%. Supposedly +/- 3.75% is an acceptable error percentage. This equates to 3/8 of one mile error for every ten (10) miles traveled.
I made a more thorough presentation the first time, but hopefully this still helps in your quest to find the proper speedo gear sets. If someone would like, please save this info for others that would like the reference.
Regards,
Carlos
I posted a reply here earlier in the day on Sunday, February 6th, only to check back later in the day and find it gone... The post was in response to the question "How to determine the proper speedo gear combination," which had been posted by Leslie (that post also disappeared).
Well, the first portion of the response is for informational purposes only - unless you are bored one night and feel like doing some mathematical computations. The primary variables utilized in speedo gear determination is speedo and tire revolutions per mile (RP/Mile), along with tire height and gear ratio. The computation matches 1000 speedo RP/mile to (x) tire RP/Mile. This ratio of course factors in tire height and axle gear ratios. It goes something like this...
Speedo Gear Calculator
1.) Determine Tire Diameter ( 225 x 60 x 14) = 24.63"
2.) Multiply Tire Dia. by pi ( 24.63 x 3.1416 ) = 77.38 tire circumference
3.) Divide one (1) mile into inches or multiply yards by inches (1,760 yards x 36 inches ) 63,360
4.) Divide 63,360 by 77.37 ( 63,360 / 77.38 ) = 818.8 RP/Mile of tire
5.) Multiply tire RP/Mile by Axle Ratio to determine driveshaft RP/Mile ( 818.8 x 4.30 ) = 3,521
6.) Divide by 1000 speedo RP/Mile (3,521 / 1000) = 3.521 (Round this number to 3.5 - this is the ratio you want to achieve).
You will now need to research the available gear ratios for your tranny and determine which combination will work best. My 86 Supra came with a 4.30 rear gear and a 35/10=3.5 speedo gear set. When I went to the 3.90 rear gear I chose the best available speedo set which was the 31/10=3.10. After doing the calculations I found myself at an actual ratio of 3.19, which ends up at a 2.8% error (3.10 / 3.19) x 100 = 97.2 or 2.8%. After correcting for my taller tires (25.1") I recalculate a speedo error of only 1.0%. Supposedly +/- 3.75% is an acceptable error percentage. This equates to 3/8 of one mile error for every ten (10) miles traveled.
I made a more thorough presentation the first time, but hopefully this still helps in your quest to find the proper speedo gear sets. If someone would like, please save this info for others that would like the reference.
Regards,
Carlos
But a RA65 manual Celica came with a lower diff ratio. I am thinking of converting my MA61 from a 4.10 to a 3.7 (I think the ratio is that) to convert my car into a highway cruiser...
Cheers.
Cheers.
ZZT231,
I ran a few numbers for you and this is what I came up with. Assuming you are running a stock height tire and going to 3.73:1 rear gear, you need to achieve a speedo gear ratio of 3.05. This can be achieved by the following combinations:
1.) 33/11 = 3.0 ratio (2% speedo error)
2.) 34/11 = 3.09 ratio (1% speedo error)
3.) 35/11 = 3.18 ratio (4% speedo error) unacceptable...
4.) 31/10 = 3.10 ratio (1% speedo error)
Now two things! One, keep in mind that a 3.75% error is supposedly acceptable, and most importantly, "try and find a speedo gear that will match the driven gear that is currently being used in your tranny." As an example, I started with a 35/10 for a 4.30 gear and only swapped the 35 tooth speedo gear for a 31 tooth one which mated perfectly with the 10 tooth driven gear. None of that tearing into the tranny mess - just a couple of minutes to complete the whole job and you are going again. If you are not sure which gear you currently have just pull the speedo cable assembly out of the tranny and look on the face of the speedo gear. It will have the two corresponding gear numbers etched on it.
Regards,
Carlos
I ran a few numbers for you and this is what I came up with. Assuming you are running a stock height tire and going to 3.73:1 rear gear, you need to achieve a speedo gear ratio of 3.05. This can be achieved by the following combinations:
1.) 33/11 = 3.0 ratio (2% speedo error)
2.) 34/11 = 3.09 ratio (1% speedo error)
3.) 35/11 = 3.18 ratio (4% speedo error) unacceptable...
4.) 31/10 = 3.10 ratio (1% speedo error)
Now two things! One, keep in mind that a 3.75% error is supposedly acceptable, and most importantly, "try and find a speedo gear that will match the driven gear that is currently being used in your tranny." As an example, I started with a 35/10 for a 4.30 gear and only swapped the 35 tooth speedo gear for a 31 tooth one which mated perfectly with the 10 tooth driven gear. None of that tearing into the tranny mess - just a couple of minutes to complete the whole job and you are going again. If you are not sure which gear you currently have just pull the speedo cable assembly out of the tranny and look on the face of the speedo gear. It will have the two corresponding gear numbers etched on it.
Regards,
Carlos
I see a lot of different numbers for the W58 and the 3:90 gear combo. I went to the dealer and bought the correct gears for a 85 Celica GTS. Which comes with the W58 and 3:90 rearend. It is a 11 tooth gear in the tranny and a 32 tooth gear on the speedometer cable adaptor. Part numbers are 33403-29125 (32 tooth gear) and 33481-22020 (11 tooth gear).
Dynamic73,
I certainly don't want to give you any bad news, but the 32/11 gear combo will probably have a greater speedo error than you would like. Go through and perform the calculations and see what you come up with.
By my calculations, the 3.90 rear gearset with 24.63" tires will require a 3.19 speedo gear ratio. The 32/11 speedo ratio will produce a speedo ratio of 2.91, which is (2.91/3.19=9%) by my calculation right at 9%. Seems as if you should be closer to a 35/11 or 32/10 for the 3.90 rear gears. Check the math - If you find yourself needing a 35 tooth speedo gear I will send you the one sitting on my desk... PM me!
Regards,
Carlos
I certainly don't want to give you any bad news, but the 32/11 gear combo will probably have a greater speedo error than you would like. Go through and perform the calculations and see what you come up with.
By my calculations, the 3.90 rear gearset with 24.63" tires will require a 3.19 speedo gear ratio. The 32/11 speedo ratio will produce a speedo ratio of 2.91, which is (2.91/3.19=9%) by my calculation right at 9%. Seems as if you should be closer to a 35/11 or 32/10 for the 3.90 rear gears. Check the math - If you find yourself needing a 35 tooth speedo gear I will send you the one sitting on my desk... PM me!
Regards,
Carlos
I haven't got the 3:90 rearend swapped in yet. So I don't know for sure if it will be off. But if you check MARQUIS111's tread which is a couple under this one. He comes up with the same thing I'm using. Also I don't really see how Toyota would use a gear that far off. This is what my parts guy told me. The RA65 used in 1985 for that combination.
Carlos,Carlos Brown said:
My car keeps on breaking down (this time electrical) and it's now not long before it's the transmission's turn in dying... Anyway, I have got access to a gearbox and diff which lived in a RA65 manual if I have time to strip it... So i'll strip the speedo gear and diff and keep it to the side so when it comes time to redo the whole gearbox, I'll change my MA61 over to a lower diff ratio and change the speedo gear with it... Think is though, is it possible to change the speedo gear in the gearbox which is paired with the matching diff and be successful?
Cheers.
Dynamic73,
Well friend, I do not know your Toyota parts guy, so I can't comment on his knowledge about cars, but most of them that I have seen struggle to read the microfiche...
Just keep this in mind, the 4:30 gearset with 24.63" tires requires a 3.5 speedo ratio, and the 3.73 gearset with 24.63" tires requires a 3.05 speedo ratio. It therefore stands to reason that the 3.90 gearset with 24.63" tires will require a speedo ratio somewhere in between the two of these. The 32/11 ratio of 2.91 is outside of this range - something to think about!
Good Luck,
Carlos
Well friend, I do not know your Toyota parts guy, so I can't comment on his knowledge about cars, but most of them that I have seen struggle to read the microfiche...
Just keep this in mind, the 4:30 gearset with 24.63" tires requires a 3.5 speedo ratio, and the 3.73 gearset with 24.63" tires requires a 3.05 speedo ratio. It therefore stands to reason that the 3.90 gearset with 24.63" tires will require a speedo ratio somewhere in between the two of these. The 32/11 ratio of 2.91 is outside of this range - something to think about!
Good Luck,
Carlos
If you are using W55/7/8 Manual
4.300 diff is 35/10
4.100 diff is 33/10
3.909 diff is 35/11 (you can use 31/10)
3.727 diff is 33/11
3.583 diff is 32/11
If you are using Auto or W50
4.300 diff is 21/6
4.100 diff is 20/6
3.909 diff is 19/6
3.727 diff is 18/6
3.583 diff is 17/6 (god forbid you are using this though)
4.300 diff is 35/10
4.100 diff is 33/10
3.909 diff is 35/11 (you can use 31/10)
3.727 diff is 33/11
3.583 diff is 32/11
If you are using Auto or W50
4.300 diff is 21/6
4.100 diff is 20/6
3.909 diff is 19/6
3.727 diff is 18/6
3.583 diff is 17/6 (god forbid you are using this though)
you know i never even though about this for the R154 anyone know what is in it?? i have my stock speedo with 3.5988888 or 3.60 dif and seem to be abit slow on the speedo.
o i have a 84 witch came with 4.30
Dave
o i have a 84 witch came with 4.30
Dave
R154 uses 32/10 gears for the early year mk3 turbos (88-late 89) and 33/11 for the later years, since they switched to a different diff (from 3:91 to 3:727)
just use carlos' formulas, and make sure it is a xx/10 gear, for my car (3.727 rear) it works out to a 30/10 working best, but i am on a 255/40R17 rear
i made a little calc program for this, you can access it at:
http://www.telusplanet.net/public/rasp08/speedogearcalc.xls
ok more info:
turns out, the difference between a 33/11 and 33/10 driven gear is really, really minor (as in, you can use a driven gear meant for a 11 tooth drive gear with a 10 tooth, and vise versa)
so heres some part numbers, if tooth numbers are double listed it means that there are two different types for different transmissions, but all the W and R series gears are interchangeable so theres no reason for the different numbers - I dont know the drive gear numbers for these pns though, just the driven gear numbers
33403-29105 30 teeth
33403-29115 33 teeth
33403-29125 32 teeth
33403-29135 33 teeth
33403-29145 31 teeth
33403-39075 34 teeth
33403-19235 35 teeth
33403-19245 31 teeth
33403-19255 32 teeth
just use carlos' formulas, and make sure it is a xx/10 gear, for my car (3.727 rear) it works out to a 30/10 working best, but i am on a 255/40R17 rear
i made a little calc program for this, you can access it at:
http://www.telusplanet.net/public/rasp08/speedogearcalc.xls
ok more info:
turns out, the difference between a 33/11 and 33/10 driven gear is really, really minor (as in, you can use a driven gear meant for a 11 tooth drive gear with a 10 tooth, and vise versa)
so heres some part numbers, if tooth numbers are double listed it means that there are two different types for different transmissions, but all the W and R series gears are interchangeable so theres no reason for the different numbers - I dont know the drive gear numbers for these pns though, just the driven gear numbers
33403-29105 30 teeth
33403-29115 33 teeth
33403-29125 32 teeth
33403-29135 33 teeth
33403-29145 31 teeth
33403-39075 34 teeth
33403-19235 35 teeth
33403-19245 31 teeth
33403-19255 32 teeth
I've found some description on my EPC..
33403-29145 31 teeth (for 31:10)
33403-29125 32 teeth (for 32:10)
33403-29135 33 teeth (for 33:10)
33403-39075 34 teeth (for 34:10)
33403-19235 35 teeth (for 35:10) (MK2 with 4.3 diff)
33403-29105 30 teeth (for 30:11)
33403-19245 31 teeth (for 31:11)
33403-19255 32 teeth (for 32:11)
33403-29115 33 teeth (for 33:11)
..and asked Mark if he could add USDM & CDN applications.
33403-29145 31 teeth (for 31:10)
33403-29125 32 teeth (for 32:10)
33403-29135 33 teeth (for 33:10)
33403-39075 34 teeth (for 34:10)
33403-19235 35 teeth (for 35:10) (MK2 with 4.3 diff)
33403-29105 30 teeth (for 30:11)
33403-19245 31 teeth (for 31:11)
33403-19255 32 teeth (for 32:11)
33403-29115 33 teeth (for 33:11)
..and asked Mark if he could add USDM & CDN applications.
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