Anyone have any experience with this? I believe there is a chart/formula out there that lets you swap the plastic speedo gear in the Tcase to match your tire/gear combo, but I have never done it - The speedometer hasn't worked in my dually since I lifted it. Taking a road trip soon and would like to have a speedo of some sort - the more accurate the better.
BW1345 and speedometer recalibration
- Thread starter fsr7
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Wyreth
Certifiable Noob
Yes there is a chart. They're manufacturer/drivetrain specific as well. I don't have one on me but they're easy to find. (ask google) Swapping the gear isn't that hard either, altho sometimes sourcing the right one can be a pain. OR you could just get a GPS speedo. Several members have mentioned having them, and liking them.
Speedometer gear calculator found here: http://gtsparkplugs.com/SpeedoGearCalc.html
And pretty much anything speedometer gear related can be found here: http://www.transmissioncenter.net/speedometer_calibration_______va.htm#ford
And pretty much anything speedometer gear related can be found here: http://www.transmissioncenter.net/speedometer_calibration_______va.htm#ford
WhiskeyBottle2
Full Access Member
Speedo
When I swapped out my 4 speed to my zf-5 I had to swap out the BW-1345 speedo gear that's inside the case cuz I found out it was wore down. Before I found a new one my speedometer only worked goofy.
Anyway...I ended up having to replace the speedo cable, the speedo cable gear, and the transfer case gear that the speedo cable hooked to. I searched & searched for new ones...The speedo cable gear and the transfer case gears have to be matched to each other and to the tire size...What a pain! Finally I found everything I needed after about six months...It seems there are not many left out there...While I was searching I bought a refurbished GPS for $69.00 at Wally World so I could at least have an idea while cruzing the big roads...
Turns out the GPS is right on time with the speedometer after I finally got it fixed....
When I swapped out my 4 speed to my zf-5 I had to swap out the BW-1345 speedo gear that's inside the case cuz I found out it was wore down. Before I found a new one my speedometer only worked goofy.
Anyway...I ended up having to replace the speedo cable, the speedo cable gear, and the transfer case gear that the speedo cable hooked to. I searched & searched for new ones...The speedo cable gear and the transfer case gears have to be matched to each other and to the tire size...What a pain! Finally I found everything I needed after about six months...It seems there are not many left out there...While I was searching I bought a refurbished GPS for $69.00 at Wally World so I could at least have an idea while cruzing the big roads...
Turns out the GPS is right on time with the speedometer after I finally got it fixed....
That's a pleasant surprise
seems like every older Ford I've driven, the speedo consistently shows about 5 mph faster than you're actually going, even though the odometer's dead-on accurate. If my truck's speedo says I'm doing 70 mph, my GPS says I'm doing 65 mph...Now, for a legitimate question
For those who've swapped from 4.10 to 3.54/3.55 gears, what driven gear did you use? And, did you have to replace the drive gear in the transfer case on a 4x4? I saw the calculator that jhnlennon posted, but it looks like you need to know how many teeth the drive gear in the trans/transfer case has before you can use the calculator, and I don't have that info in front of me right now...and was hoping someone might know off the top of his head.Thanks
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Thanks lennon, those were the links I was looking for. Looks like that transmission center site is out of stock on a lot of the ford stuff, but once I pull my system apart and see what all I need I'm sure they've got some knowledgable people source part #'s etc. Thanks again.
Most likely you will only need the driven gear, and they show 16-21 tooth in stock. If you need a higher or lower tooth count, you will have to go with a ratio box which they also have(at a cost).
Most drive gears I have seen are 7 tooth(on Fords anyway).Now, for a legitimate question
Thanks
bike-maker
Full Access Member
When I swapped from 3.55 to 4.10 gears, I pulled the speedo gear out of the truck with the BW1356 transfer case and put it on the end of the speedo cable on my truck and bolted it right in my truck's current BW1345.
The speedo gear that went with the 3.55 gears is dark red and has 16 teeth on the gears.
Can't tell you what the 4.10 gear looks like, as it's still in my truck.
The speedo gear that went with the 3.55 gears is dark red and has 16 teeth on the gears.
Can't tell you what the 4.10 gear looks like, as it's still in my truck.
Thank you both Mike, I presume your speedo's currently reading reasonably correct (i.e. within 5 mph or so)?
Mike, I presume your speedo's currently reading reasonably correct (i.e. within 5 mph or so)?
Shadetreemechanic
Full Access Member
BTW if you have a dealer nearby, the gears are right at $5 bucks there. My dealer had a box of them to choose from.
19 should be a 410 speedo gear, 16 is what I have also to be pretty close with 355. tried a 15 and it ate it right off, it was dead on till the teeth left, it was the wrong pitch for the drive gear, listed for a car or something.
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