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Slip in a new diff!

Posted: Tue Jan 06, 2015 7:53 pm
by Morrisminormo
Since my 1098 upgrade for my 1957 (948cc) saloon, I feel I need to change my differential ratio. It flies up hills and pulls like a train ( you get my drift :wink: ) on its original 4:55 ratio but 50/55mph sounds like it's enough for the old girl! If I change to a later 1098 minor diff 4:22, is it just a case of drop the old and in with the new? This is my daily driver and I do 55 miles a day, so don't want to blow another engine!

I have a 948cc engine with big ends just started to knock if anyone's interested, with unleaded head less than a year old :D

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:13 pm
by bmcecosse
Yes - one out and one in. Won't make a huge difference though.......

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:19 pm
by simmitc
The 1098 diff will fit a 948 axle BUT you'll have a problem filling it with oil - the 948 diff has the filler plug on the front of the diff, whereas the 1098 axle casing has the filler plug on the rear of the casing. So, with a 1098 diff in a 948 case, you won;t have either hole :o

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:49 pm
by Morrisminormo
bmcecosse wrote:Yes - one out and one in. Won't make a huge difference though.......
I thought I may help me cruise at 60/65?

My old minors seemed to have more top end than this one

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:49 pm
by minor65
55/60 mph IS more than enough for the old girl. No matter if 948 or 1098.

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:50 pm
by Morrisminormo
If it was worth me doing, then a drill And a helicoil set is all I need.

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 8:54 pm
by Morrisminormo
minor65 wrote:55/60 mph IS more than enough for the old girl. No matter if 948 or 1098.
I agree that 60mph on 7 inch shoes is more than enough. I just wanted to drop the revs a little. I do have a rather loud exhaust on her that makes it sound more painfull than it really is.

Nice looking car you have there, very much like my own :D

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 9:02 pm
by bmcecosse
You can simply fill the oil in through the breather hole....

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 9:05 pm
by minor65
Ahhh right. Lower revs :D

Thanks, it's a 61. I only have it 6 weeks. I am the 2nd owner and it still has its original 948. My other 2 minors are 65, so 1098's. This will be the first 948 I will have driven and haven't yet as I'm still working on it.

Re: Slip in a new diff!

Posted: Tue Jan 06, 2015 9:30 pm
by Morrisminormo
minor65 wrote:Ahhh right. Lower revs :D

Thanks, it's a 61. I only have it 6 weeks. I am the 2nd owner and it still has its original 948. My other 2 minors are 65, so 1098's. This will be the first 948 I will have driven and haven't yet as I'm still working on it.
This was my first 948 too, the engine was super sweet, until the big ends went :cry: but I've upgraded to 1098 engine and box and the difference is remarkable.

I'm the 3rd owner from new, mine is 1957, I still use the trafficators :D what work you doing on yours??

Re: Slip in a new diff!

Posted: Wed Jan 07, 2015 6:10 pm
by minor65
Have a look in the restoration section and all will be revealed.