Dang i watched a video of changing out that gear before and seems something I don't necesarily want to mess with lol. That whole pin lining up thing and such but I might take to a guy who did one years ago and I don't remember him dropping the trans but he did have a lift.22 tooth will eat itself up in no time. 21 tooth driven gear is about as tall as you can run. You need to pull the tail hosing off the T5 and swap in a six tooth drive gear. With the tires you have and 3.73’s you can run a 18 tooth driven gear and be within 1-2 mph.
ok thanks I will try itI made a tool that can help anyone who knows their speedo drive gear, tire specs (i.e. 275/40/17), and rear gear. It will calculate the exact driven gear needed and round that to recommend the nearest tooth count. Then you can input what you actually choose (i.e. 21 instead of 23), and it will tell you how far off your speedo will be at any speed.
I also use it all the time for gear ratios & tire sizes. I've shared that gear calculator here. I've gone back to this for every build, every trans swap, every rear gear swap, every change in tire size, etc... I've found it extremely useful. I've also collected data over the years on various transmission gear ratios, rear gear options, and available tire sizes of interest to me which are below the calculator in the spreadsheet.
It may look complicated at first, but it's very simple as long as your computer can use excel. Just stick to the highlighted cells. Only the highlighted yellow cells are meant to be changed. You'll get an error if you try to change anything else. I've protected it without a password. You can unprotect it if you want to make modifications to other cells.
<Link to the file on my share drive>
I think you will need to download it and open in excel. Google sheets may not be interactive.
appreciate the insight and actually I've taken a trans out before and taken 2 engines out and put an engine in and complete exhaust, ect. The one video I watched of swapping the gear it was something about aligning the pin back correctly or something IIRC that seemed kind of like it could be a PITA and to get it to stay at the correct orientation or something but I will check out more videos and see.I figured if I was going to the trouble of changing the drive gear in the trans I was going to a six tooth so that no matter what I decided to do rear end gear wise and tire wise I would not have to mess with it again. That was about 20 years ago and never regretted it.
Being afraid of tearing into a T5 to change the speedo gear is almost not warranted as they are like Legos. If you have access to a lift then pulling the T5 is an easy job but I have only had that luxury twice (my dad's shop has never been less than 3 hours away). Literally its pull the exhaust center section, drain the T5, remove the shifter (give the T5 time to drain), remove the drive shaft, remove the transmission support and slowly let the end of the T5 down (it will stop but watch everything so you don't pinch a wire, etc.), remove the (4) 15mm hex head bolts that hold the T5 to the bell housing, and its ready to come out. I usually use my floor jack to hold the weight of the T5 and just slide it back and out of the bell housing. Once it's out of the car watch one of the hundred or so videos on how to remove the tail housing. Swap the gears, clean the back of the T5 case and the face of the tail housing and reassemble. This would be a good time to make sure the tail housing bushing and seal are in good shape. Getting the bushing out and new one in is a pain without the right tools so if you do not have that skill set you can either have a shop do this. If you are jammed up on time buy a used tail housing and have the shop swap the bushing and seal for you so you have it laying there when you do the work. The General or Mike may have one or two laying around?
It is not that hard to do and taking it to a shop to swap out a $20 plastic gear is pretty costly. If the T5 needs to be refreshed and you are not comfortable with that I totally get it but this just is not that complicated or at least that is my opinion.
is in an 8 tooth that's oem in the 94 cobra? Forgot to hit send to reply to you so when i went back and replied to 5L5 it multi quoted lol6-tooth just means you can run a smaller driven tooth count. The teeth are a little thicker, so less prone to shearing off.
Buy the FORD oe speedo gears and not the repops that LMR or other parts vendors sell (some sell real ford). I have a pile of them, and the Ford teeth are sturdier than the repops. I've run a 7-tooth drive gear with 21-tooth driven gears for years without issue.
This chart refers to factory OE configurations and tire sizes, so only use it for speedo gear part number if you have changed things.
Middle part number is 17271, so if you wanted a 20 tooth black gear, look up part number C1DZ-17271-A
is in an 8 tooth that's oem in the 94 cobra?6-tooth just means you can run a smaller driven tooth count. The teeth are a little thicker, so less prone to shearing off.
Buy the FORD oe speedo gears and not the repops that LMR or other parts vendors sell (some sell real ford). I have a pile of them, and the Ford teeth are sturdier than the repops. I've run a 7-tooth drive gear with 21-tooth driven gears for years without issue.
This chart refers to factory OE configurations and tire sizes, so only use it for speedo gear part number if you have changed things.
Middle part number is 17271, so if you wanted a 20 tooth black gear, look up part number C1DZ-17271-A
ok. I might just order a 23 tooth and see how much off the speedo will be. It didn't seem to change much from the 20 to the 21 tooth still seemed to be about 20 mph off. How much closer do you think it'll be off with the 23?Yes. They started putting 8 tooth drive gears in the T5’s in 1990.
how much can I expect to be off with the 7 tooth and the 21 with the 315 30 18? Since i have that already I can see just using that vs buying more stuff. Doesn't have to be perfect as I was off 7 mph on my 95 setup with 295 35 18 and 3.55 gears. I can't remember what drive gear I changed to but it was a black 20 tooth.6-tooth just means you can run a smaller driven tooth count. The teeth are a little thicker, so less prone to shearing off.
Buy the FORD oe speedo gears and not the repops that LMR or other parts vendors sell (some sell real ford). I have a pile of them, and the Ford teeth are sturdier than the repops. I've run a 7-tooth drive gear with 21-tooth driven gears for years without issue.
This chart refers to factory OE configurations and tire sizes, so only use it for speedo gear part number if you have changed things.
Middle part number is 17271, so if you wanted a 20 tooth black gear, look up part number C1DZ-17271-A
Cannot access it at work lmao...............Use the tool!
You can lead a horse to water...
it won't let me make changes on your sheet and said I needed to request accessUse the tool!
You can lead a horse to water...
oh my bad I must've missed the part where I needed to download first lol. I'll have to do it at home though or maybe on my phone later. I did call LMR a few times and found out some useful info as well though. So it seems that for every tooth it only changes the speedometer 2-3 mph either way depending on if you are going up in teeth or down. So yeah the 23 tooth with my 8 I'll still be off 12-15 mph vs 20 but still too much. I was able to get in touch with my old Mechanic who did my first engine swap back in the day as he has a lift and changed one out for me before.I saw you request editing permissions and granted them. I intentionally did not allow editing permissions so that it was the same for anyone. The intent was that you download it, and adjust it once it's on your computer. That said, I don't care that much, because if you change it, I can replace it from the one on my local hard drive.
gotchaNo possible way to remove the tail housing without removing the shifter and driving the roll pin down just enough to release the detent block (block on shifter rail that the shifter ball goes into). Once that is done you slide the tail housing back being careful to capture the ball and spring under the block.
Hey so what about on a lift and is it possible to do all of that or not even on a lift but if the car is on jack stands is it possible to leave the trans in remove the shifter ball, in other words can you drive the pen out enough and put it back in can you get to all of that decently with the trans still in the car?No possible way to remove the tail housing without removing the shifter and driving the roll pin down just enough to release the detent block (block on shifter rail that the shifter ball goes into). Once that is done you slide the tail housing back being careful to capture the ball and spring under the block.
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