Differential Oil Level

[ericbushby]

Thankyou William but I have to state that it was not my idea in the first place. Someone on this forum did it a few years ago, and like you I thought- yes, that is a good idea.
Yesterday we fitted one in a friends Series 4. and of course the first thing he did after cleaning up was to check the oil level. He seemed well pleased. It took longer to find the correct socket than to check the level.
Eric in Burnley
1967 S3SE DHC

[Larry C]

After seeing the access hatch, I got a boat fitting and installed it on my Sprint. Just fabulous. I used a hole saw to make the opening and it went like a dream. definitely worth the (small) effort.

Larry carbonetti
'73 Elan Sprint

[tonyabacus]

Eric
Nice job with a professional look about it. Well done and will likely be taken up by many owners as word gets round.

You said you put a reinforcing plate to beef up the flimsy fibreglass area around the fitting, but for clarification did you put this on the inside or the outside of the hole. Also what did you use to cut the large hole as that too has a good look about it.
Tony

[tonyabacus]

William

Can you give an approximate measurement to the centre of the access cover from the edga of the fuel tank please, as you appear to be directly in line with the diff filler.
Tony

[smo17003]

Hi Tony,

I have done the same mod after reading this topic a few years ago. The size of boat hatch that is required is 4". To fit it you have to cut a 4.1/2" dia. hole in the GRP. If you can get one, use a holesaw.
The OD of the fixed part of the hatch is 5.3/4". I had a 6" square piece of aluminium sheet that I used to add strength to the hole (you have to cut a 4.1/2" hole in it to match the hole that you have cut in the GRP). The ali sheet goes the other side of the hole to form a sandwich of ali/GRP/hatch. 6 x 4mm screws and nuts fasten everything together.
If you don't have a piece of aluminium then you could just add a layer or two of GRP to increase thickness in that area before cutting the hole.
When cutting the hole in the GRP you need to be aware that you have the chassis diagonal bars in close proximity.
You can purchase the hatch from Ebay for about £6, https://www.ebay.co.uk/itm/395495094359 ... BMqI_v2aVk

Edit: notice that Eric's is more to the left than William2's. I made mine more like the latter to avoid the chassis and also gain slightly better access to the handbrake tree.

Mike

[smo17003]

William

Can you give an approximate measurement to the centre of the access cover from the edga of the fuel tank please, as you appear to be directly in line with the diff filler.
Tony

Tony,

If you look at William2's photos the RH edge of the access hatch is directly above the RH chassis bolt. That is what I used as a reference.

Mike

[tonyabacus]

Hi Mike
Thanks for all the details, just what I needed. I was aware that the chassis bars were going to be close hence my questuion, so your comment is duly noticed.

You indicated that the hole is also close to the handbrake tree, so are you able to get to it easily for greasing?
Tony

[ericbushby]

Hi Tony and others
I cut the hole in the front panel with a 4" holesaw but measure your hatch first. The hole was a bit small so the edges were ground out to fit. The fibreglass there was wavy and flimsy so I fitted a 3mm thick aluminium disc sandwiching the glass.
The disc was tripanned out on the lathe faceplate and drilled and tapped to suit the holes in the hatch.
Having cut the hole I realised that a bit to the right would have lined up with the filler plug and given better access to the handbrake tree.
However this turned out OK as later it allowed me to fit a priming pump in the corner. (Weber carburettors you know

DSCF0479

We fitted these hatches to four cars in our local Lotus club.
I have never had to grease the tree since then, so I do not know about that.
It now takes longer to empty the boot than check the oil level.
Eric in Burnley
1967 S3SE DHC

[smo17003]

Hi Mike
Thanks for all the details, just what I needed. I was aware that the chassis bars were going to be close hence my questuion, so your comment is duly noticed.

You indicated that the hole is also close to the handbrake tree, so are you able to get to it easily for greasing?
Tony

Yes Tony, plenty of access to both. There is one other thing to check that I hadn't noticed when I installed it (I just checked it 10 minutes ago), that is the LH handbrake rod runs very close to the GRP. The clevis for that rod is very close to the part of the hatch that protudes through the hole - see William2's final photo to see what I mean. It's more luck than judgement that mine just clears it. If I was doing it again I would start by making the ali plate first, and using that to mark out the hole's location from underneath (I know, easier said than done), before cutting the hole.

Mike