Diff Weight and CG?

[greyV8pete]

I need to modify the cradle of my lifting jacking gadget to enable safe diff removal.

Does anyone know the following please.?

1. The approximate weight of the Marlin diff assembly i.e. the 7" diff unit plus the side mountings / outriggers?

2. The centre of gravity (i.e. the point of balance) of this same assembly, when viewed from the side (i.e. looking along the drive shaft)?

I am hoping that the cradle will support the whole thing at its point of balance so it doesnt try to fall forward or backwards when it is lowered, hence the questions. Peter.

[CABRIOBOB]

Re: Diff Weight and CG?

I just lay down under the diff and lift down or back up, but you can put your trolly jack under and lower iit down holding on to it to stop it falling off the jack when you lower it. I didnt find it that heavy, just needed someone to hold the support bolt heads when undoing the nuts, you can use a pair of mole grips to hold the heads if your on your own.

[Peterx]

Re: Diff Weight and CG?

I guess it depends on how big and strong you are but having just done this on my Sabre I would warn against lying under the diff when removing it.
I'm a bit of a weakling and I certainly could not support the weight of the diff and undo the bolts. It would likely fall on my face or chest and be very painful !!
I would put a trolley jack (or maybe a scissor jack) under the diff about 2" in from the edge of the back plate. Take the weight of the diff on the jack and then slowly undo the bolts. You'll need to hold the diff with one hand to stop it falling off the jack. Then lower the diff to the ground.
It's easy to lift a diff off the ground in free air but under a car it's bl**dy heavy!!

Take care and try and get a helper if you can.

[dcunn]

Re: Diff Weight and CG?

Wish I was a strong young man like you Bob..................any day now I'm planning to drop mine (the diff that is !).....and like Pete have concerns.

Pete FWIW I have a spare 7 inch diff on the bench ready to go in, and I reckon it's too heavy to lift with one hand and I'm still planning how to "out"
the old one and "in" the new....may be easier with the tank out ? NB mine is "push in" shafts, so your Lobro may be heavier

Good Luck DC

[Robert in Cumbria]

Re: Diff Weight and CG?

What I have done with heavy stuff, and mean HEAVY, like bulldozer gearboxes and stuff. Is to sit the component on a decent board with chocks and packings nailed to the board to hold it stable, then to stop it rolling off maybe a strap to tie it down to the board, then put a brick or similar under one end, then another brick under the other end. You can of course use wooden 'bricks' or concrete blocks, or whatever you have to hand. Add these packings thick or thin, as required to reach the desired height. The point is you are only lifting it a bit at a time and under control. If it's really heavy you can use a lever to raise it each time.

[greyV8pete]

Re: Diff Weight and CG?

Many thanks for all your input. I have used Robert's technique in the past to jack a Fiesta onto a "pillar" of 4 concrete blocks at each corner ,wheels suitably chocked all the time. It was like having a mini 4 post lift!

Will post a photo of my gearbox removal "gadget" if it works ok for the diff. Peter.

[copperleaves11]

Re: Diff Weight and CG?

I have changed the diff a couple of times, single handed. With a half decent trolley jack and an improvised wooden cradle i'ts quite easy to lift and align the whole assembly. David

[greyV8pete]

Re: Diff Weight and CG?

I have changed the diff a couple of times, single handed. With a half decent trolley jack and an improvised wooden cradle i'ts quite easy to lift and align the whole assembly. David

Many thanks David. My "gadget" should be ok then. Peter.

[Peterx]

Re: Diff Weight and CG?

I would put a trolley jack (or maybe a scissor jack) under the diff about 2" in from the edge of the back plate.

I just checked my photo's again and it looks like the CG is more like 3" from the back cover.

...peter

[greyV8pete]

Re: Diff Weight and CG?

I just checked my photo's again and it looks like the CG is more like 3" from the back cover.

...peter

Many thanks Peter. That's about what I hoped. The diff should be coming out today, that is if I can brave the freezing wind which is blowing straight into my garage Peter.

[dave_clutterbuck]

Re: Diff Weight and CG?

Wish I was a strong young man like you Bob..................any day now I'm planning to drop mine (the diff that is !).....and like Pete have concerns.

Pete FWIW I have a spare 7 inch diff on the bench ready to go in, and I reckon it's too heavy to lift with one hand and I'm still planning how to "out"
the old one and "in" the new....may be easier with the tank out ? NB mine is "push in" shafts, so your Lobro may be heavier

Good Luck DC

Hi Dave
My petrol tank is currently out for repair. With the car on car ramps there is plenty of room underneath for easier access to the diff. All told it took me about 30-45 minutes to remove the petrol tank. If or when I have to access the diff at a later a date I will definitely remove the petrol tank.
Regards
Dave

[greyV8pete]

Re: Diff Weight and CG?

.... The diff should be coming out today, that is if I can brave the freezing wind ......

The lifting cradle was ready and fits well, but alas the wind won! With no useable fingers after 15 mins it was: Freezing wind 1, Diff removal Nil! I have now purchased some blue plastic to make a portable garage extension! Perhaps tomorrow it will be out ! Peter.