Hi, I can't figure out what this knocking noise is on my 1960 f-100. the engine is a 223 , 3 speed column change. All the gears engage great & the truck drives lovely...but everytime you pull away in 1st gear there is a knocking noise (which goes when you depress the clutch) It only makes this noise in 1st gear... it sounds like someone tapping the underside of the floopan with a hammer....

anyone else had this???

 

I'll take a shot at it. If it only happens in first gear and you can definitely hear it coming from the floor pan, not internally in the transmission, I think it could be either a bad transmission mount or you linkage is hitting something, that's if you have three on the tree. It's just my wild guess. Why I think it happens only in first is because that's when you have the highest toque and it's making the transmission twist the most.

It's just my shoot from the hip wild guess, I don't really have an actual experience to pull from.

 

Or, it could have a broken tooth on the first gear or the portion of the cluster gear that engages first gear. Check out the mounts first though.

Lou Manglass

 

Thanks Bob, thanks lou......I will investigate the mounts....i can't pin point the excact area down, (The tapping on the floorpan quote was just so i could get across the sort of sound it is making, rather than where it is coming from) sorry, should have made that clearer. But i understand what you mean about the torque, i will add though, it makes the noise the minute you start to move regardless of the speed your doing....and the knocking does speed up/slow down with the rpm .

steve.

 

Could be U joint? Sometimes they make strange noices at different times. It's worth checking out too. Drive through an alley or along a wall on the driver's side with your window open and see what you hear coming from the outside of the truck.

 

You might want to check the adjustment on the shift rod.

I had one do that in my 55. What was happening was the rod was not quite getting it all the way into first gear. Then when it engaged it would "pop in" the rest of the way. You might be only talking about 1 or 2 turns of the locking nuts on the shifter. Sometimes this will happen if you took a turn a little too fast with old cab mounts and your cab slipped to the side a dash (like 1/8 inch). (that will very slightly change the angle of the shift column from cab to steering box and torque the shifters either up or down just a dash). I'll bet it goes into reverse REAL EASY.

Just a guess.

If that isn't it, post a picture so we can see what it sounds like!

 

Hi Julie..........yep, it goes into reverse like a silk glove.

 

What's your history with this truck? Is this something that just started after being quiet or is it something you discovered as soon as you got it on the road?

It sounds to me like a bad tooth or gear, or if it does it also in Reverse, the countershaft needle bearings could be bad. The bad tooth would have to be really bad; almost missing, which would mean there is a chunk floating around in there...

 

Ok I've been thinking about this today and I need to ask a question. Do you just get one thunk, or a thunk thunk thunk all the time in first?

 

Julie.....That's excactly what i get....A thunk thunk thunk all the time in first gear. As soon as you shift to 2nd it goes....It shifts through the gears fantastic....the only slight crunch i get is back down from 2nd to 1st when the truck is rolling. When the truck is at a standstill it goes into first no problem and they as you start to move ..thunk thunk thunk etc...if you dip the clutch the thunk thunk thunk goes away.....

Ross...It's been doing this from when i bought the truck into the uk.

Thanks for all the replies so far....I really appriciate your help folks...

steve.
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I think I'd take the driveshaft out, and spin the tranny in 1st at idle speed, get under there and see if the noise is in the gearbox for sure. (Be careful!)

 

Take a look at your transmission mounting bolts. Years ago I had a 1973 Dodge van that had a similar problem, would make a clunking noise every time I pulled away from a stop. I took it to a dealer and turns out Dodge had a technical bulletin out for the problem. Seems that year had a problem with the transmission mounting bolts loosening and allowing the transmission to move under torque. Very easy fix, hope you are as lucky.

 

Ok that makes a difference. It's not the shift rod adjustment then. If it was it would be just one thud .

Your transmission is a light duty that is not synchroed in first gear. So, it will shift up to second and between second and third, but you will almost have to stop to get it back down into first - that's normal. I might venture to say someone didn't know that, tried to slam it into first and busted a few teeth off first gear in frustration.

If the noise persisted into second gear - say at a low speed, they I would venture to say U-joint. And since it doesn't do it shifting to other gears, I would elliminate the clutch (a possible broken spring on the clutch plate).

If you jack up your truck and drain the fluid out (and check for metal chunks - I think wil be there unless the PO already cleaned them out), then disconnect the shift rods, and pull off the side plate, you are probably going to discover a gear with a couple teeth missing. If it makes the sound in reverse as well, then it's your primary First/Reverse gear (the one that the shifter slides front and back). If it doesn't do it in reverse, then it probably the first gear (I think it's gear 7102 above-been 20 years since I've played with one of these).

I'll see if I can find a picture of one open and get back to you. But from what you describe, I'm almost certain you've got some busted teeth - don't fret, they are plentiful and easy to replace - actually, it's easier and probably about the same cost just to find a good used transmission.

 

Hi Steve,

I didn't write that up quite right above - know what I was thinking bu the fingers typed it so the eyes will see the wrong thing.

Gear 7113 is your primary drive gear. When you are in first, the smallest gear on it in the back is driving your "first" gear-which I think is 7100. If the noise only happens in first and reverse, then 7100 is probably chipped. If it happens only in first and not reverse then the small gear on 7113 is possibly chipped- from the sound of it, what ever is chipped a full tooth maybe two. I'll see if I can't find that picture - it's hard to tell from this drawing

Point is I think you've got chipped gears.

Sorry about the confusion.

 

Thanks Julie......it only does it in first for sure....reverse is ok...so i guess i am looking at this right?...Ford Fairlane trans gear 6 & 8 cyl. 1960-62 223 & 221:eBay Motors (item 140129881191 end time Jun-05-09 11:04:04 PDT)