The Stovebolt Site Forums The Parking Lot Big Bolts 2 speed rear end and speedo

My speedometer did not work.
Ordered a new speedocable.
Did not help, the only thing was that the crappy plastic end was worn down.

Today I removed the whole speedounit.
And the 2 speed vacuum gearbox on the rear end of the speed was JAMMED BIG TIME.

Grease that was like concrete !!

So I just removed it permanent.

What will be the effect?

Speedo will show correct speed on HIGH gear? Or low ?

I will try to fix the vacuum gearbox, but did the classic TEAR-APART-SUPER-FAST-and- don't-remember-how-it-was-before

The speedometer will now be correct in Low Rear only.

Don't forget the odometer will not add up correctly either when running in High Rear.

Mike B

CRAP, that's not what I wanted to hear... I will need to fix this adapter then, or get a new one. Anyone who has one that works laying around "unused" ?

What is the differance between HIGH and LOW, is it 10% or 20% differance?

There are speedo units on EBAY than can convert up to 200% and down with almost 60%

Ulf,

The speedometer 2-speed adaptor is calibrated to match the same ratio as your Hi and Low gears. Your 1959 will have 9.04 Low and 6.50 Hi ratio gears, so in Hi range your speedometer cable will spins 29% slower than in Low range.

Mike B

Thanks Mike.

I found this on EBAY:
http://cgi.ebay.com/ebaymotors/Spee...arts_Accessories&hash=item1e60a98b52

They had a homepage where you could order " increase or decrease " gears.

They had one that increased 28% and that will have to be as close as 29% as I can get.

I just will have to remember it will not be accurate in LOW gear. But it's much more important that it is correct in HIGH.

Thanks again
/Ulf

Hy lastchancetowing, just to clarify, Mike said correctly that you want to DECREASE the speedo cable speed to the speedometer head, not increase it, to make it read correctly in high range, hope that clarifies.

Mike said that my speedo will turn 29% slower in HIGH gear. Which in my head makes me want to increase speed with 29% ?!?!?

HELP, Am I wrong here ?

Ulf,

In Low range the driveshaft turns 9.04 times for 1 revolution of the tires. In Hi range the driveshaft turns 6.50 times for one revolution of the tire, so Hi range has the speedometer cable turning SLOWER, so the adaptor speeds it back up by 29%.

I drive all of my 2-speed rears the same. I start with the transmission in 2-low then go to 3-low then 4-low then 4-hi, which makes 4-Hi kind of like having OverDrive. The difference between 4-low and 4-Hi is .71 (6.50 divided by 9.04 = .71 which means your engine will run 29% slower to maintain the same speed you were running in Low range).

You should be able to lock your existing adaptor into Hi range with a piece of tie wire. No need to buy anything, or you could put a choke cable on it and move it manually for whatever range you are driving in.

I hope this helps clear it up...

Mike B

Thanks... it's clear now...

Will try to put the old adapter together again.
Since the vacuum valve seemed fine, I think I can get it to work.
If not, I will just by a new gear and live with the low gear fault speed.

Br /Ulf

Or just throw an old gps unit it there are use it as the speedometer.

That's not okay in Sweden. Speedometer must be connected to electrical circuit, and get power when you turn the key.

It shall be installed as a unit in the truck, not removable.

Sadly... On the other hand IF it should break, the cops can't say anything if you use a GPS out on the road, because THEN it is okay

SWEDISH F**K laws and regulations

Ulf;

Take a look at ebay item # 260841042969. The parts you need may be there.

SimS

I didn't know that was the law.... Amazing!

Ulf,

The aBay parts SimS has you looking at could work, however I'm not sure the ratio percentage is the same from the 40's to your '58...you would need to comfirm that.

If your looking for another adaptor I think I have one with a bad diaphram. It could be made to work manually like the one on eBay. I've never been able to find replacement diaphrams, and all of the used adaptors I've found the diaphrams are bad...

Mike B

I checked my own diaphragm, and it's also bad... looked fine at first glance.

I could make it work manual as you suggested.
But I will buy the gear from EBAY so at least it's correct in HIGH gear.

Ulf,

The existing adaptor will work fine if you manually put it in High Range, you don't need to buy anything. More than likely the only thing wrong with your adaptor is the diaphram went bad not allowing it to shift, the gears inside the adaptor are probably fine.

Mike B

No the gears were not fine.
They were stuck like in concrete, and I just took it all apart to clean it.

Still the gears move very bad ( hard to turn ) so I have already bought that gear from EBAY since I have to have it for registration check within 14 days.

I will of course try to fix the original one, and the hose, and change the diaphragm. Cause I really want it to be original as possible.