I 100% agree with dalmatiangirl61 that the best way to remove a damaged gear is to cut it as close to the shaft as possible. This tends to reduce the force of the press fit and usually they will come off with less force.
When installing the replacement put the shaft in a freezer and the gear in an oven. This will temporarily reduce the force required to press fit but you MUST act quickly before one cools and the other heats. Think about it beforehand and have everything ready to go.
Hello professionals. I’m having a hard time getting a gear off a countershaft in a transmission.
It’s an interference fit and the manual warns it will take up to 20 tons to press it off.
However, I’ve tried 20 and a 100 ton presses with heat on the gear core and still won’t budge.
It did break a few teeth off unfortunately, so I stopped there for safety and to keep from ruining the shaft.
I’m hoping for some tips or tricks from the machinist community of professionals - someone has to have faced and conquered this kind of issue.
Most of the stuff I would say has been covered, heat fast with the biggest O-A torch you’ve got. It’s the temperature difference that counts.
Expansion is weird. Remember that the material expands in all directions equally, if you just heat the center it’s constrained by the cold material around it and actually tries to expand into the hole. You need to heat the whole part to get hole in the center to open up.
You mentioned heating from the outside in. I’d heat halfway in from the edge. If there’s center boss you’ll have to throw some heat directly on there once the rest of the gear is hot.
A tap from a hammer will sometimes break things loose. Doesn’t even have to be in the right direction, just a little shock to get things moving when constant pressure won’t.
What type of car is the trans going in, anyway?
You said Ford transmission (C4?) so I don't reckon it's got a bow tie on it.
back in the day when there were lots of TD24 dozers about,no one had the big pullers to get the sprockets off to replace the drive bearings and seals........anyhoo,they would pull off the outer housing with the bullgear inside ,sprocket outside ,and lay it down across a couple of logs,sprocket up.........then they would get a track roller shell ,place it over the shaft ,and put a piece of gelignite and a fuzed cap in it......boom,and the shaft was neatly removed from the sprocket with no damage.
A real plumbers blow torch puts out more heat then most acetylene torches. I mean the old school pump gas torches not a propane torch. there is a difference between heat and temperature.
I’ll be picking up an OA torch kit Monday and getting it filled - unless I can find one used nearby for sale.
I’ve been using one of the plumbers propane torches so far.
I didn’t realize just how critical it was to heat it fast - but now I know!
My plan keeps changing, but now I plan on picking up a cooler of dry ice on the way home from getting a torch. I’ll freeze the entire assembly (shaft and gears) then set it in the press, apply oxy torch from middle in and around the boss, while adding pressure.
Thank you very much for the advice.
It’s an MT82 6 speed manual that’s used in newer model Mustangs (up until 2018 when they made some changes and named it the MT82-D4)
This one is modified with heavier duty, treated internals, and other upgrades for power handling.
Ah, gotcha. I haven't messed with any of the newer Ford transmissions. I'm still rocking a 4R70W in my F150 (and a non-synchro 3 speed in my 52 Ford)
Oh, another thought, put a gear puller on it, get it as tight as you can, and while it's on there tight, heat the gear and try driving the gear off by hitting the hex head on the gear puller with a hammer.
The combo of constant force, heat, and the shock from the hammer might do the trick.
OOORRR do what John said - get you a big ass tub of Tannerite and go that route.
Prolly going to want to blow it up anyway, if the oxy fuel torch, dry ice, and whatever else doesn't work.
Blowing it up is on the list - down toward the bottom, but the list is growing shorter.
Thanks for the tip on keeping the torch set upright. I had heard that years ago from either my brother or my nephew (both used to use them regularly) but they didn’t explain why - just remember them telling me to keep it upright in its carrying case.
I tried to look up BTUSs for a blow torch and got nowhere. Idiots calling a propane torch a blow torch. There is a difference. The fuel is different, The refilling is very different, preheating is not needed for one etc. etc. Reminds me of people calling a lathe a drill press.
I know I was talking about removing big gears but the torches the welders used were huge. With the nozzle like a CocaCola can drilled full of holes at the end. They liked to light up the torch near to you so when it ignited with a flame about 6 ft long you jumped out of your skin. Welders think things like that are funny ! They tuned the flame back to a blueish white jet 2 or 3ft long, then they’d go to work. Two guys with a torch on either side of the gear.
Those are know over here as a Rosebud tip.