How to remove the stuck gears from a gearbox shaft (dried oil). Advice appreciated (1 Viewer)

[Economist LC76]

I‘ve decided to use a NOS gearbox for my car. The gearbox stored 40 years somewhere…

I have to replace the input shaft (FJ to BJ) and slightly refresh the surface rust.

The gearbox cover was easy

I was lucky to find all SST equipment and to reassemble the gearbox

Where I was not so lucky, it is to move the gears from the shaft. Dried oil works like glue
No hammer / no SST / no press.
Any ideas how to tackle this problem? Bathing in ATF or solvent/ hot water / heat gun up to 150grad C?

May be someone had a similar experience? I appreciate the advice.

 

[Steamer]

I have to replace the input shaft (FJ to BJ)

Are you replacing the input shaft or the output shaft? The picture you show with the puller on it, is the output shaft.

Here’s a pic of the removed input shaft on my 4 speed H42.

 

[Malleus]

If the only thing holding the gears on the shaft is oil, yes a solvent is best. You can warm it to help speed the process, but most solvents are flammable so you need to check the ignition temperature first. If oil isn't what is holding it on, you need a puller or press to do the job correctly.

Be very careful with flame or high heat, since the gears are heat treated. Unless you are going to toss them, then go ahead and anneal them.

 

[Economist LC76]

Are you replacing the input shaft or the output shaft? The picture you show with the puller on it, is the output shaft.

I replace the input shaft. They are different for FJ and BJ. I didn’t put the picture of it here.

 

[Economist LC76]

If the only thing holding the gears on the shaft is oil, yes a solvent is best. You can warm it to help speed the process, but most solvents are flammable so you need to check the ignition temperature first. If oil isn't what is holding it on, you need a puller or press to do the job correctly.

Be very careful with flame or high heat, since the gears are heat treated. Unless you are going to toss them, then go ahead and anneal them.

Thanks!

 

[locklaw]

Leave the shaft in a bath of diesel overnight. It's much slower than using acetone but you won't have flash rust issues afterwards. Otherwise, first an acetone bath followed by a diesel one for rust prevention.

 

[Economist LC76]

Leave the shaft in a bath of diesel overnight. It's much slower than using acetone but you won't have flash rust issues afterwards. Otherwise, first an acetone bath followed by a diesel one for rust prevention.

Thank you! Being a great fan of Diesel, I never had a diesel bath! Need to try

 

[Economist LC76]

Leave the shaft in a bath of diesel overnight.

Diesel is unfriendly to the Nature.
I’ve decided to use a heat gun with a sensor: heating up to 60-70 grad Celsius + plastic hammer.

Now the gears are cleaned & oiled

For those who have a similar issue: heating up to 60-65 grad works great! I’ve used 500 grad Celsius hot air, heating each gear gently, constantly turning a shaft, checking the heat distribution. When the temperature is reached, you need to gently tap the gear with a plastic hammer while turning the shaft.

 

[Paul_A]

Kroil--put that sh*t on everything!

 

[peesalot]

You did a nice job cleaning, lubing & reassembling, looks good, I would be stoked to have a NOS fj transmission.

 

[B y r o n]

Ed's Red.