Muncie leak query

[Mad4slalom]

Hi all , some may have been reading about my missing bearing support bolt that rattled out . I have been losing oil through the bolt hole. I have been keeping the oil level full and using sparingly. My query is and hoping for some opinions on is that I read that the muncie 4 speed does not have a front seal on the mainshaft but a slinger that throws the oil back int the box. I also read that if the box is over filled then oil will escape into and drip out of the bellhousing. I notice that if i fill til the oil runs out of the level plughole then it seems to chuck a lot of oil out initially and then once the level has dropped to a half inch below the fill hole then it seems to lose oil at a much slower rate. I think i have been losing more oil because i have been over filling. I am now still checking after every run but only topping up to a half inch below plughole. I am finding that the level is not dropping half as much as it did when filled right up to overflowing.
Any thoughts appreciated , tia ps i will at some time be pulling the trans to sddress the missing bolt.

 

[Oneball]

Yes no specific seal, but the oil level is way below it so it’s not just going to pour out. I think you’re losing oil from the bolt hole when you brake. I wouldn’t like to be running it low all the time, the gears are only splash fed.

 

[Mad4slalom]

Yes no specific seal, but the oil level is way below it so it’s not just going to pour out. I think you’re losing oil from the bolt hole when you brake. I wouldn’t like to be running it low all the time, the gears are only splash fed.

Thanks oneball, I keep checking it after each run so it should not get low enough to do any harm. Still not sure of which saw or cutting wheel will be easiest to use to cut the gearbox crossmember . I want to do it with the trans supported in situ, the top of the crossmember is quite tight to the fibreglass floor.

 

[Oneball]

You don’t need to cut the crossmember, the box comes out really easy if you remove the mount and shifter.

 

[Mad4slalom]

You don’t need to cut the crossmember, the box comes out really easy if you remove the mount and shifter.

Some say it is really fiddly and a removable crossmember to my mind is a no brainer, have the flange kit here already . Dont know why the factory made the auto box x member Removeable but not the 4 speed . I may try to remove box with crossmember in situ , then if i get stuck I will fire up the saws and grinders

 

[Oneball]

Getting it out is easy, push it back and it’ll basically fall out. It’s putting it back that’s tricky

 

[Mad4slalom]

Getting it out is easy, push it back and it’ll basically fall out. It’s putting it back that’s tricky

Ok but i read you have to lower back of motor avoiding damage to distributor, and rotate trans and wangle it down and out.

 

[Grahamred70]

It is a bit fiddly but not difficult, set your engine at TDC No. 1 doesn't matter if firing or exhaust it's only for reference, pull your distributor to be safe when you drop the rear of the engine marking where the rotor arm is. Disconnect prop shaft at the diff and pull the prop shaft back until it comes out the back of the trans. Console out disconnect linkages and pull gear lever then it's as you said pull the box back roll it on it's side and it's out, I seem to remember I had to seperate the bellhousing fron the box while it's still under the car, it's been a while since I did it to re hash my gear ratios after rebuilding the diff to a cruising ration instead of the drag strip one it came with!!

Graham

 

[Mad4slalom]

It is a bit fiddly but not difficult, set your engine at TDC No. 1 doesn't matter if firing or exhaust it's only for reference, pull your distributor to be safe when you drop the rear of the engine marking where the rotor arm is. Disconnect prop shaft at the diff and pull the prop shaft back until it comes out the back of the trans. Console out disconnect linkages and pull gear lever then it's as you said pull the box back roll it on it's side and it's out, I seem to remember I had to seperate the bellhousing fron the box while it's still under the car, it's been a while since I did it to re hash my gear ratios after rebuilding the diff to a cruising ration instead of the drag strip one it came with!!

Graham

Thanks for the info, what is it , half a day ish . These jobs are often not as bad ss we fear once we actually get sround to tackling it. What height of the floor did you raise the vette to drop the box . I have a single post ramp but no good for the trans as a great lump of ramp iron crosses under the car . I made some cribs to raise about 8” under the tyres so hopefully enough to drop box .

 

[Grahamred70]

Hi Mad,I drove the front up on to normal car ramps and then jacked the back end up on to axle stands so it was more or less level gave ample clearance to get under and drop it down, mind you I was about five years younger and a bit more agile then!! Download the relevant parts from the Chevy manual and take it step by step, it's not difficult just a bit fiddly at times getting things in the right position to get them out!

Graham

 

[Oneball]

No need to do anything to the bellhousing. I didn’t remove the dissy or drop the back of the engine. You do need to remove the gearbox mount and it’s plate.

 

[Mad4slalom]

No need to do anything to the bellhousing. I didn’t remove the dissy or drop the back of the engine. You do need to remove the gearbox mount and it’s plate.

View attachment 26771View attachment 26772View attachment 26773

Thanks for those pics oneball, that makes me feel more confident anout getting down and dirty.

 

[Mad4slalom]

Hi Mad,I drove the front up on to normal car ramps and then jacked the back end up on to axle stands so it was more or less level gave ample clearance to get under and drop it down, mind you I was about five years younger and a bit more agile then!! Download the relevant parts from the Chevy manual and take it step by step, it's not difficult just a bit fiddly at times getting things in the right position to get them out!

Graham

Thanks graham , all these first hand accounts of actually doing the job are reallY helpful and really appreciated.

 

[Grahamred70]

Thanks for those pics oneball, that makes me feel more confident anout getting down and dirty.

I remember now, I was fitting a new clutch as well as changing the ratios in the gearbox and changing the diff gears for more relaxed cruising, which is why the engine needs to be lowered at the back to get the bellhousing off, so you're correct if the clutch is staying there's no need to drop the back of the engine, like I said it was a few years ago.

Graham

 

[Mad4slalom]

You don’t need to cut the crossmember, the box comes out really easy if you remove the mount and shifter.

Hi oneball, you know when removing the muncie trans, they say you have to lower the back of the motor? Do you have to loosen engine mounts or do they flex enough on the rubbers? Why does the motor need to drop? Is it to access top bellhousing bolts or to achieve the correct angle to slide box back? TiA

 

[Oneball]

Hi oneball, you know when removing the muncie trans, they say you have to lower the back of the motor? Do you have to loosen engine mounts or do they flex enough on the rubbers? Why does the motor need to drop? Is it to access top bellhousing bolts or to achieve the correct angle to slide box back? TiA

I didn’t lower mine. I think it’s only if you want to remove the bellhousing. If you’re just removing the box there’s no need to remove the brllhousing.

 

[Mad4slalom]

I didn’t lower mine. I think it’s only if you want to remove the bellhousing. If you’re just removing the box there’s no need to remove the brllhousing.

Good news , I wonder if as someone suggested on here a while back if I could just pull the box back enough to access the bearing support and replace the missing bolt and add the french locking tabs, any thoughts

 

[Mad4slalom]

I didn’t lower mine. I think it’s only if you want to remove the bellhousing. If you’re just removing the box there’s no need to remove the brllhousing.

May be a silly question, can I replace clutch and flywheel without removing bellhousing,

 

[Oneball]

May be a silly question, can I replace clutch and flywheel without removing bellhousing,

No.

If you want to do that I’d take the box off then the bellhousing.

 

[Mad4slalom]

May be a silly question, can I replace clutch and flywheel without removing bellhousing,

Ignore that silly question 🫣