I am having front end issues. I bought the front end repair book by Chaffin and the video. They are both very helpful!
I thought the perches were on correctly, but now that the square ruler shows a positive caster (axle top leans forward) I have to trouble shot.
Do theses look like they are on the correct side?
Thank you in advance. Bob
I think they're backwards. The top of the axle should tip toward the rear of the car.
They look backward. The small hole on top should face towards the rear.
Perhaps this diagram will be of some help:
Looking at your pictures compared to the diagram, it looks like Eric is correct, your axle is on backwards.
Using your picture, the boss I circled should face towards the rear of the car, not the front.
Great thanks! I read the same book the picture cam out of and still missed the positioning of the boss on the perch! Glad I asked.
This is why I call the car, 'the car the forum built!'
They are backwards. Please swap them around before driving the car or you could really hurt someone. These things are suicidal with negative caster.
If the cater is off, does that mean we're all not going to get our sandwiches?
Sorry, Bob, I couldn't resist....
When you turn the axle around, make sure your spindles are correct also. I can not remember what side the left hand thread is on from memory. You may need to switch the spindles out or they may have been correct and you just got the axle in wrong. Someone here should be able to say what side the left hand thread is on......
There's another, easier way to tell the front of the perch from the back. The hole for the radius rod on each perch has a radius cut on the rear side. Look here at a rear view of a pair of 1911-15 perches (yellow arrow points at the radius):
The front side has no radius (blue arrows):
When Eric says to swap them around, what he really means is to just remove the axle assembly and turn it around. Yes that means to remove the wishbone and install it from the other side!! Then that job is done.
Then read what Donnie said about the spindles. The spindle threads should be so the threads LOOSEN when you are driving the car forwards. So the RH wheel should have the LH thread and vice versa
I guess this is a dumb question. Why not just change the perch? This avoids the spindle issue unless they are somehow backwards. I don't see how that would be, however. If all this is too much work, there is an axle wrench that can adjust the axle angle without changing the perches. This also gives the experts something to notice and talk about and could avoid a serious discussion on some other parts that could be wrong on the car.
The left hand thread is on the right side of the car, or at least it was on my car that I just took apart.
Changing the perches from one side to the other is only easy for those who have never done it.
I have never done it, but I have tried a few times.
OK, I have a basic question regarding front axle work on an assembled car.
How do you safely support the car while removing the axle? There don't appear to be any solid support points once the axle is removed.
Jack stands under the frame rails about by the crankcase arms, or as far forward as you can reasonably get them.
Once the stands are in place you can jack up the front axle a bit on each side to remove the king pin and tie rod end on each side.
Now undo the radius rod to perch nuts.
Undo the shackles
remove the axle and turn it end for end and do everything up
The tie rod can actually stay in place and the radius rod stays connected to the pan.
If it fights you, you can always remove the spring and radius rod and do it out from under the car.
Jackstands on the frame . . . Jack 'er up with a floor jack under the front axle then install the jackstands somewhere just forward of the 2 rear motor mounts. Remove the wishbone, drop the axle with spring, perches and spindles; spin the axle 180 degrees, swap the spindles around, reinstall the axle assy, take a break and get a beer.
Bob -- There are a couple of ways to go about fixing your situation. IF the perches are not "frozen" to the axle, you can remove the perches and swap them around. IF the perches ARE frozen to the axle, it will be easier to turn the axle around with the perches still in it. IF the spindles are now on the correct sides, you will need to remove them from the axle and keep them on the same sides when you turn the axle around. (The spindles might not fit the same on the opposite end of the axle.) If the spindles are on the wrong sides now, leave them and the perches on the axle when you turn it around, and all will be correct.
Thanks for the tips on supporting the front end, guys. Didn't mean to sidetrack the discussion. I needed to know and figured Robert would need to know as well.
The perches have a part number casting near the top 3818 is right and 3819 is left
Please do not jack the car up by placing a floor jack under the middle of the front axle! The only safe way is by jacking the car up from under the spring perches.
Model T front axles are very strong, yet they bend very easily. When you put a floor jack under the center of the front axle and jack the car up, you will likely put an upward bend in the axle. This will throw the king pins out of alignment. They are suppose to be precisely perpendicular to the axle (as are the spring perch holes - all four were drilled at the same time.). When the axle is bent upward, this changes the angle of the spindle bolts. They will point inward at the bottom instead of being parallel. This will I turn throw off the camber.
Need I also say that wrapping a rope around the middle of the axle to tow the car creates a forward bow in the axle?
Arguably, the Model T front axle is the most neglected part in the restoration.