MTFCA Forum

Does anyone know for sure if a '25-'27 steering gear set (5:1) will fit OK in a 1914 steering gear box? I find the original 4:1 a tad too direct at highway speeds (40-45 MPH).

There was a recent thread on this question and many in the past. Some solutions were provided
http://www.mtfca.com/discus/messages/50 ... 1427982436
to see the rest https://www.google.com/search?q=1926+27 ... nt=gws-wiz

From an 2011 post by John Regan the pitch is different on the Ford drawings for the 5 to 1 gears . So unless the case is worn they will not fit. Best to change case with a later case. Dan

The late 25 -26 -27 Steering gears will not interchange with the pre 25 steering gear case.
There are major differences in the gears.


Read the Ford T Service manual page 181 beginning at paragraph 772. There are pictures and detailed information about the differences in the gears and cases.

There is a lot of information in the service manual that can be a real help in trying to work on a T. It really helps to refer to it and you’ll be surprised what’s in it.

The vendors sell a kit with the gears and shaft that be used in the older Model T’s.

John: I have exchanged maybe 6-7 early ('19-'24) 4:1 gear sets with the later 5:1 sets with zero problems. I am aware that the pin spacing on the main shaft and all the 4 gears are different from the 4:1 and 5:1 gear sets but I've never tried the exchange in a earlier brass car. The sets sold by the T vendors are basically correct replacements for either of the stock ratios, and not for simply designed for changing the ratio.

I am always on a budget when I build stuff and trust me,I tried used 5-1 gears in a used 4-1 case before going to the trouble of cutting rivets,and there is no way even I would try to run the wrong gears in the wrong case. It may work in a worn out case,just because of the wear but I would not trust it.
That is my experience,your mileage may vary.

The 4:1 internal gear has 36 teeth. The 5:1 internal gear has 38 teeth. The spacing of the pins for the planet gears is substantially different for the 4:1 and 5:1. I would NOT mix and match any of the parts.

It worked beautifully in my 1909 column. Had to machine the cover a bit due to differences in the length of the spud shaft. Otherwise no issue going 5-1 in an early case. Mine was a complete new setup from birdhaven. I think as long as you change everything including the main shaft you will be good to go. They even made me a custom length shaft to match the shorter 1909 column.

Looks like some think that only the three small planentary gears are different and don't realize that the main (sun) gear as well as the main shaft with different pin spacing must be changed as well. I plan to use a complete used 5:1 set (with the main shaft) in my 1914 brass box so will hope that there is already some wear in the existing box gear.

Bruce, You should be ok using the complete set of 5:1 parts : main shaft, sun gear, 3 planet gears. You will need 3 short planet gear pins. When you have your steering gear apart another thing to check on the 1914 gear case is the rivets, make sure that they are tight and in good condition. There was once a supplier that sold a thin fiber washer to go between the case and main shaft to protect the expanded rivet heads in the steering case.

They did not work without changing the shaft on a 1921, as they were different sizes in diameters.

The 5:1 and 4:1 both interchange within the main housing and are the same diameter but the pin spacing is different since the gear diameters are different (all three planet gears and the main drive sun gear).

Bruce Compton wrote: ↑

Sat Jul 23, 2022 1:53 pm

Looks like some think that only the three small planentary gears are different and don't realize that the main (sun) gear as well as the main shaft with different pin spacing must be changed as well. I plan to use a complete used 5:1 set (with the main shaft) in my 1914 brass box so will hope that there is already some wear in the existing box gear.

I was not aware of any difference in the gear case other than the slot cut for the longer one pin. I did this same conversion plus a larger diameter steering wheel on my 14. For the same control reasons @ speed. ALL the guts must be of the 5-1 set (no mixing) Center shaft, 3 small gears & long steering shaft. I also gave her more caster 5/8" as compared to the stock 3/8" This added more straight line stability. She handles very well at speeds above 60.

Agree John. I have used a larger steering wheel at times too. I also came across a shorter (1" shorter) pitman arm and it helped as well.

I made the conversion on my '14 speedster. I used green time saver and an electric drill to work everything in and the result was a nice smooth set up. It took time and patience but the results were worth it. As stated above everything except the gear case itself was for the 5-1 set up no mix and match.

Here is link to an old post about this. Read what John Regan says.
http://www.mtfca.com/discus/messages/17 ... 1302106072

Thats interesting. I didnt consider the idea of using all or some repop 5-1 components. My thinking is use the pieces from an original 5-1 column, which is what I have always done.

So is the claim that original parts dont interchange, only work in a very worn case or that repo parts conversions dont work?
( Anecdotally, my gear case/steering seemed tight before the conversion.)
If its the latter, I would be aghast to discover a repop part didnt work/fit correctly or was nonfunctional.

Another related observation. The 3 gears originally were .375" & the pins undersized for clearance. The replacement pins are .37500", but work nicely with worn, used gears & tighten some of the slop out. The wont work with NOS gears without some clearance grinding.

would someone kindly tell me if a file can mark the repro gears?
if they can be marked, do you feel they are fairly soft, or have been heat treated?

I've made the conversion for folks 3 times. Each time it was a pisser. I don't have any repro parts on the shelf or I'd test them myself and not be asking the question.

thank you

Scott_Conger wrote: ↑

Sun Jul 24, 2022 8:20 pm

would someone kindly tell me if a file can mark the repro gears?
if they can be marked, do you feel they are fairly soft, or have been heat treated?

I've made the conversion for folks 3 times. Each time it was a pisser. I don't have any repro parts on the shelf or I'd test them myself and not be asking the question.

thank you

I have tried a file on a set of repop gears, they are hardened. These gears came from a local(costa mesa mfg) He distributes them widely. Thats not to say he is the ONLY manufacturer of these gears. I cant speak to his dimensions being exact to Ford spec. I heard tell of his new tripple gears fitting a bit tight in the gear mesh.

Thank you John

I have had same results as J R with good cases. If case is worn the 5 to 1 gears will go in. If not they will not. Now if you use old worn gears and a worn case they may fit ok. I have not tried new reproduction gears, due having a supply on real NOS gears. I used to also buy every 5 to 1 column at auctions I saw. Got to start parting that stuff out.
Herm had a post on this subject talking about a cutter he had made to turn inside of case some 5 gears would fit. Never saw pictures, wish I had.

I have changed the steering many times. The trick is to change the steering shaft and all internal parts of the steering case. You must use a 5 to 1 steering shaft, pinion and gears, and the gear pins. There seems to be no difference in the cases.

You might considered staying with the 4:1 gearing, assuming everything from the road to the steering wheel is tight and in good adjustment, and adding a 17" steering wheel and adjusting caster/camber to the best advantage and setting toe-in to slightly favor understeer. Adjusting front/rear tire pressures might also be of benefit. Anything you can do to lower the car's center of gravity will improve handling. The condition of the rear suspension and engine mounts can affect handling, and any defect in the front suspension will degrade handling.