Is there a way to get my speedometer to read correctly? Apparently my rear-end gears were changed in my 48 delivery. (216ci 3-speed manual) . I also replaced my tires with radials the same size as the tires I removed. (Just a bit wider.) I dont know the actual ratios, however I have tried two different speedometers and they both have read 5MPH less than I am actually driving. I confirmed this by following a car with cruise-control engaged in the lead-car while communicating with the driver via cell phone. I again tried it following a different car and get the same result. There must be a way to correct for this? Thanks!
Changing the speedometer won't do anything, you generally correct the speed with the gear that goes into the transmission. One with more teeth will give you a different reading than one with less teeth. Not sure how it is done on your particular trans, but they used to also sell an adapter that changed the ratio. I think United Speedometer sold it, if they are still around. Don
Contact Elwood at Speedometer Service in Colorado Springs (719-632-3165). Great guy to work with. He made a speedometer cable that fit my 350 turbo to my original Nash speedo. Also told him how far off my speedo was and he sent me the correct gear for my tranny. It is spot on! Stevie
Thanks I visited United Speedometer's website and indeed still in business. Looks like they will be able to help me out! I will also check out Elwood. Thanks! You got to love the HAMB!
Beware of United Speedo, I sent them the gauges speedo and clock out of my 41 Chevy two years ago to get retrofitted. Said they needed $750 to get started on them, got charged that amount and am still waiting on them. Had to buy another set up and sent to Bob's Speedo in Michigan and got 'em back in 6 weeks. Repeated calls and reporting to the BBB in Riverside CA has done nothing to get my originals back.
Thanks for the "heads-up". I'm so tired of some of the vendors I use, that tell me what I want to hear, then once I give them a deposit, my stuff seems to fall into a black-hole! Not to mention the sudden change in attitude from these bozo's! For instance, how many times do I have to send my transmission back to “Man-Trans” until I finally realized they screwed me? I feel, they know exactly what they are doing, and hope I will finally get tired of swapping the dam transmission out! NEVER! It took months, not weeks to send their first attempt, again months for the second attempt, And will soon be going back again. ASSHOLES! I have an original ’41 3-speed I have been using instead. It’s an ole’ rattle-box, but at least it works! Dyno-tested my ass. Perhaps a good thread would be “List your Crappy, Rip-Off Vendors here”. For HAMB-ers to check before using someone’s services. Peace, and better luck in the future!
Well it got pulled. I suppose I can't blame the HAMB, it is probably not a good thing all said and done. And I don't want them to think I don't respect this place. I do! But I did try! Got to admit, it would have been a popular post!...lol We all know some of these vendors deserve it!
as long as you know the difference and it's 5mph, is it worth the time and expense to adjust? least this way you won't get speeding tickets
Yes, I have been working with that premise. I wasn't alerted there was a problem, until I flew by the cops doing 50 in a 40. I figured I could get away with the standard under 5MPH over the limit. One look at the officers face said it all. I figured I better check it out! He didn't come get me, so I figure he must like old cars. Lucky day!
I thought your speedo was 5 mph faster than actual speed. But what do I know, 4 years after getting my car on the road and still haven't hooked up the speedo. Just finishing a trans swap so maybe it's time.
Nope it reads 5 MPH slower than I actually driving....no biggie, I don't always communicate as clearly as I should in forums. Yeppers....having a speedometer here in the Boston area is super important. Usually, as a rule of thumb, people will drive 5 MPH faster than posted, and figure that is generous enough for those who insist on driving up your butt. Usually, the police will not ticket you for only 5 MPH over. Without a speedometer, you might be throwing a wrench into the whole system here? I did it for a while and all I could do was pace the car in front of me. If there was one. Drivers in the Boston area remind me of a swarms of angry hornets! I think we are famous for maniac drivers! BTW: Nice ride you got there.
They have an electric speedo so you can adjust it yourself. However, I didn't wan to go through the hassel of putting a new speedo in so I took my car to a speedo shop. They put the car on rollers, ran it up to 60 mph, replace a gear in the trans and now it's dead nuts on at 60. Cost was $65.
Here is the problem with that Blackball thread as I see it. Sooner or later every vendor out there would end up on it. The reason I say that is because anyone who has been in business for any length of time HAS to piss someone off eventually.......it just happens. But just because I had an unpleasant experience with a company doesn't mean that 10,000 other people didn't have a great experience with the same company. We see it all the time on here where someone will bitch about a company and a bunch of other people will say they love dealing with the same people. Just part of life and doing business. I dealt with United years ago and they were fine in that transaction, but I did hear they had some issues during a move or something like that. Don
You need a gear with one tooth more than what you have now, that will slow the cable enough for 5 MPH. Or you can calculate the ratio needed, most speedo's turn 1000 RPM at 60 MPH. Tire circumference in inches divided into a mile's worth of inches times rear end ratio gives driveshaft speed. Count the teeth on the speedo drive gear and...well, maybe just go one tooth bigger!
Thank you! Elwood has offered to take care of it for me....and at great price! I do understand that, however I can see a need for some way of rating vendors..good and bad...For example, eBay's method will represent the occasional malcontent without destroying the seller. But,if the seller has multiple negative feedbacks...you can see that too. Actually,there are more vendors I would love to recommend than warn about! I'm in agreement with, the kind "removal of thread" msg from HAMB. It states, they are not really into that here. However, I do see a gap that needs to be filled, and perhaps someone will create a web-site that will cater to patrons of auto related vendors.
I wasn't trying to get anyone in trouble on here, but just wanted you and others to be cautious about dealing with them based on my experience. I saw a thread on here that a shop that had used them had the same problem I did, but it was after I had already sent everything to them. I understand why nobody wants anything to do with a rating system on vendors, everybody is gonna piss somebody off at sometime. I did use a GPS for a speedo while mine was getting worked on and used it to check the accuracy of it afterwards. Hope you got yours working right!
A lot of these guys come up with different methods of calibrating a speedometer but I have found that a simple way is to run down the road at a set speed (say 50 or 60 mph) and use a handheld gps to figure the difference. If you don't have one, one of your buddies or coworkers most likely does. That will give you a spot on actual speed and not the speed of your buddies car. Then figure the percentage of difference and figure out what speedometer gear changes you need to make. There are also speedometer calibration boxes that have little gear sets in them that look like quick change gears that you use to calibrate the speedometer. With one of those you don't have to take the trans apart and it's easy to recalibrate it if you make a tire or rear gear change. You should be able to find one of those at most semi truck dealers or semi truck parts houses. If you see an old Ryder rental/lease truck in the junk yard look under it as many of them have that gear box to correct the speedometer. Another good source for speedometer drive gears and general info http://www.transmissioncenter.net/speedometer_calibration_______va.htm If your speedometer works smooth and the odometer works smooth I wouldn't touch the speedometer it's self.
I hope I can jump in here with a question. I have a '56 Ford, 292 V-8 with a '61 Ford COM transmission. My original '56 Ford rearend is a 3:22 and the gear in my transmission is not correct for the rearend. When my speedometer reads 70 mph I am going 60 mph according to my '07 Ford F-150. So do I need to replace the speedometer gear with a gear with more teeth or fewer teeth? And by how many teeth to achieve a 10 mph correction? My tires are P205/75/15 and are 27 in diameter.
The Ford speedometer driven gear is 5% per tooth, so going by your figures you are reading 16% fast so you would need to go 3 teeth more than the gear you are using now to slow it down 15%.
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