MGB Register Forum

my 1967 mgb roadster dipstick has sustained severe perishing of the rubber grommet that stops the dipstick from going too far down the dipstick tube and therefore incorrect reading of oil level has happened, I cannot find anywhere the information as to how far up from the tip of the dipstick to the bottom edge of the grommet should be placed.
I have been told quite naturally to empty my oil, renew my oil filter and refill with the correct amount of oil. Before I have this done and to save me that trouble does anyone have the same dipstick and therefore able to measure for me their dipstick arrangement.

Hope someone in the forum can help please.

thank you

Brian Annable

Brian
The part you call a grommet is actually named as Gaiter.

It is part no 181735 and is found on page 25 of the current Moss Europe parts book referred as 69 in the drawing on page 24.

The name gives the clue - it is a gaiter (or cover) to prevent dirt entering the sump.

It definitely not a stop for the dipstick which is why you will not find a measurement anywhere for its position..

A new one fitted will slide on the dipstick as you enter it into the sump to find it's own natural position. The dipstick should be gently (so as not to bend it) pushed down until it touches the sump. Then you can measure the sump contents correctly. The gaiter should stay in position on the dip stick.

Hi George,
thanks for your comments and advice, I have been away so not able to reply.
I still had a nagging doubt and decided to renew oil and oil filter with quantity guidance from my mgb handbook. Using the correct amount of oil after flushing all old spent oil out and refilling,
the dipstick without a Gaiter went to the bottom of the sump and showed oil level as very over full so by trial and error placed the Gaiter eventually to the point where the oil level showed as full.

At the bottom of the Gaiter is now a line etched onto the dipstick in case the same happens again and the Gaiter is very securely in place.

The dipstick does not touch the bottom of the sump, and oil was clearly being read as full or overfull prior to the new Gaiter being fixed. My oil level was clearly too low but thankfully not sufficient to cause damage and very low mileage anyway because of the winter months.
Pleased I caught the problem before good summer mileage.

Hi Brian

Out of interest what is the distance from the bottom of the dipstick to the gaiter either the top or the bottom of the gaiter.
Thanks
Regards
Rob

Hello Rob

It's 255mm to lower of gaiter and 296mm to top of gaiter.


I have secured the gaiter to the dipstick at the top end by cable tie and scored the dipstick level with top end of the gaiter for a reference point just incase it moves again or perishes.

regards
Brian

Many thanks Brian will check mine this afternoon

Rob

My friend and I had cause to compare dipsticks recently (* ye not missus). He has a 68 and I have a 71. I'm pretty sure if you have a gaiter like he does then the dipstick is intended rest on the botton of the sump. Mine has a register half way up and a bung that goes inside the tube. When we compared, his was about 15 mm longer than mine (stoppit) but Identical in other respects including the marks. You cant take the capacity in the manual too literally. For a start when you drain the oil there is normally half a litre left in the cooler and pipes.

for what it's worth here are my observations relating to both MGB and Midget dipsticks:

# after having had several examples of each engine I've noticed that there are some differences in the dipsticks fitted, but I couldn't offer any specific information. This being the case it seems possible (perhaps likely?) that many engines will not have their original dipsticks fitted and that this would lead to "errors" in measurement.

# My '72 MGBGT (owned since 1978 so perhaps likely to have the original dipstick) has a 18V engine and the dipstick has a fixed metal collar, below which sits a rubber grommet to act as a "cushion" and seal when the dipstick is in place. So - neither are adjustable. If I fill the engine with the recommended amount of oil it is usually overfilled. Main thing I think is to keep an eye on the oil pressure gauge, as long as you have some pressure and the oil level is approximately correct I don't think ordinary road users need to worry.

# My '61 MK1 Midget has a dipstick (which I have no idea of its provenance) which is plain steel (double stem of course) which simply clonks down onto the sump pan when you insert it into its place. So obviously the sump pan acts as the stop. Seems to be just as accurate as the MGB dipstick as far as I can tell!

IanF

Having changed the oil in my Roadster recently, I took the opportunity to take some pictures and measurements of the dipstick, which I hope will help the discussion here. The car is a 1969 Mk2 with 18GG engine, which although not the original engine it was a like for like replacement supplied by Mechspec.
The collar on the dipstick is permanently fixed to the split shaft by a crimp above the collar and a second crimp below the steel sleeve. The grommet stops oil splashing out or the dipstick tube, the end of which is flared so the grommet seals completely when the dipstick is pushed fully home. All the parts and relevant dimensions of the dipstick are shown in the picture. The dipstick doesn't touch the bottom of the sump.

[attachment=0]Dipstick.jpg[/attachment]

Interesting.

I have a 77 car. The rubber gaiter on the dipstick has become hard and no longer seals the tube in which the dipstick sits. As a result there is some blow-by of gases which carry oil droplets. These coat the area around it. There is not much but it looks messy.

I tried soaking the dipstick and gaiter in brake fluid in the hope that it would be absorbed by the rubber softening it and causing it to swell slightly. But that didn't work. I can't see an easy way to replace the gaiter or fit an additional seal. So I am considering a new dipstick.