diff swap advice

i will be fitting an experimental 3.54 rear diff fairly soon and would it be ok to use blue hylomar as a sealent on the mating surfaces?,,
initially i am only fitting the rear as i want to see if i get on with the new characteristics before i commit to the full changeover,
regarding the oil, i presume i can fill the diff by measuring the correct amount and then get it in either through a half shaft tunnel with that corner jacked up or through the breather hole?,
if i get on with the gearing i will be fitting the proper pan with a filler plug,
any advice would be welcome
Ryn

Blue hylomar fine, think you need to leave it awhile before joining diff
So no filler plugs in casing or diff? if so I can’t see an issue with either of your filling methods

Take a good while for EP 90 to get down the breather hole.

thanks,oil in through the hub end then,
as a small and simple job invariably leads to more on these would it be advantageous to buy any seals which may get accidently damaged in advance,
if so any pointers to which seals to order in a worst case scenario,
Ryn

rynner said:

i will be fitting an experimental 3.54 rear diff fairly soon and would it be ok to use blue hylomar as a sealent on the mating surfaces?,,
initially i am only fitting the rear as i want to see if i get on with the new characteristics before i commit to the full changeover,
regarding the oil, i presume i can fill the diff by measuring the correct amount and then get it in either through a half shaft tunnel with that corner jacked up or through the breather hole?,
if i get on with the gearing i will be fitting the proper pan with a filler plug,
any advice would be welcome
Ryn

Click to expand...

Yes thats how i do it

rynner said:

thanks,oil in through the hub end then,
as a small and simple job invariably leads to more on these would it be advantageous to buy any seals which may get accidently damaged in advance,
if so any pointers to which seals to order in a worst case scenario,
Ryn

Click to expand...

Yes diff gasket and output seal and two half shaft flange gaskets, if you take the flanges off the half shafts you will need 2x fibre seals but if just removing halfshafts with the flanges you won't need them

thanks,
it was an earlier post by yourself that gave me the tip regarding the oil filling.

Yeah tbh i'm fed up with it as it can be a pain but ha ho

Is it not possible to drill the casting of the diff in the same place for a filler plug?

Very early 3.5 diffs have the filler plug in the casting same as the series ones
Cant be to hard to drill the diff pan/weld a nut to it and use a normal bolt with copper washer as the level/ filler plug?

Re 3.54 diffs, what engine are you running ? 2.25 diesel will struggle, I managed a couple of weeks before reverting to 4.7s and yes the engine was good after a decent rebuild.

at the moment i have a spare 3.54 diff sitting in my workshop doing nothing, i will be fitting it just to see for myself first hand how it goes as the reviews are varied, if i am happy with the setup i will fit the same on the front and weld a new diff pan on with the filler hole on the rear,my diff pan is fairly worn already so needs doing soon, if not to my liking then off it will come, possibly an overdrive may be something for me to consider in the future if one comes up, i have recently rebuilt the 2 1/4 petrol engine and it pulls well with no issues at all with the power, i generally am able to pull away in 2nd and then go straight into top, very seldom do i have to use any other gear for any significant amount of time,
i drive unladen on mostly country roads and at 45mph in top it feels like i should have another gear hence the experiment.
i have 205/80 tyres on it, atm the speedo shows about 38 when driving at a measured 30,
i also have a lpg system to fit but that is definitely on the backburner for now,
ryn

With 208's you should be fine but will find a use for first.