hit reverse gear on occasion

[Clampit]

My 803 engine and gear box are running very well and I am not bothered about going more than 50mph in my 4 door series 2 but, I have been known to hit reverse gear on occasion which I really hate doing. I have read about a mod. by T.K. Marshall by welding in a step of metal so that to select reverse the gear leaver has to be lifted but I cannot find the article. Does anyone have a copy of this please or can link me to it. All the links I have followed go to a blank page. Thank you.

[myoldjalopy]

Hmmmm......well, thats a bit odd as the 803cc gearbox was designed with a mechanism requiring you to lift the gear stick to select reverse, thus eliminating the problem you mention. So if you have an 803cc engine and gearbox, you shouldn't experience this problem. Are you sure someone hasn't created a 'hybrid' 803/948 gearbox without transferring the reverse selector rod from the 803 to the 948 internals? I assume you have the long 803 gear stick still?
There is an article by T.K. Marshall in the old hard copy Tech Tips book, but that is about creating the hybrid 803/948 box. However, on the same page, there is an article by Bryan Finch about creating an 803/1098 gearbox 'hybrid' and, indeed, this does mention welding in a 'slug' of steel into the bottom of the slot in the reverse selector rod.
I can try and copy and post this page if you wish.......

[myoldjalopy]

There is some further information about this topic on this page: https://www.mmoc.org.uk/Messageboard/vi ... 1&start=20

[Clampit]

There is no STOP on my box when going across into reverse and as a result it makes me nervous. I am pretty confident it’s a 803 box but it could be possible that my reverse leaver is missing that PIN that requires you to lift the gear stick. I will take the stick off and see if I can see it. I think you are right, having thought about it, the weld mod. is for the 803/ 948/ gear box modification.
Thank you for your help, I will let you know what I find.

[Declan_Burns]

Here's the article about the 803 /948 gearbox mod.
Regards
Declan

[myoldjalopy]

Well done, Declan. That saves me having to copy and post those articles.
Clampit - notice that the 'weld' method is for the 803/1098 conversion, not the 948 conversion.......as stated before, the 948 conversion is effected by swapping the 803 reverse selector rod into the 948.
Be interesting to find out exactly what you do have fitted and why you are having this particular problem.

[ManyMinors]

Definitely sounds as if somebody has fitted the 803 gearchange to a 948 gearbox to me. I remember doing the same to mine when I had a Series 11 many years ago. It was indeed a bit easy to touch reverse on the move

[Clampit]

Just to put you in the picture, the gearbox was sold to me as an 803 box and after fitting it, I was very pleased with it apart from this problem “hit reverse gear”
I assumed this is what they did until myoldjalopy’s reply that it should not happen and I
think now it must be a 948 box with an 803 backend. I took the stick off and drained some oil out and took some pics. of the one in the car and my old 803 box .
Just to check, I fitted the gear stick into the old box and yes, you have to lift the stick to go into reverse. So that’s that, I’m going to have to take the whole lot out to fit the 803s reverse selector rod. Good job I’m retired.
Thanks for your help.

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803.jpg (121.23 KiB) Viewed 1984 times

[myoldjalopy]

..........and good job you have an 803 reverse selector rod to swap in too!
Glad you solved the mystery.

[ianmack]

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Assembling my 803/948 box I was able to compare the two reverse rods. The 803 one on the left shows the step which prevents accidental selection.

[ianmack]

18652DA5-2A13-407A-8AC5-C6783B08A3C7.jpeg (980.42 KiB) Viewed 1691 times

My box of gearbox bits also produced this one, with a ramp rather than a step. I’m guessing this is from a 1098?

[philthehill]

The operating shaft pictured above Pt No: 22A198 is fitted to a 803cc/948cc gearbox.

On some of these selector shafts BMC were up to their usual tricks in making the casting number on the item one number out from that stated in the parts list i.e. Reverse fork shaft cast number on the rod 2A3304 - number in the BMC parts list 2A3303.
The original BMC Pt No: was 8G603.

[ianmack]

The 22a198 rod could be fitted in a 948 box but in an 803 there would surely be still the risk of inadvertent reverse selection?

[philthehill]

There were three reverse selector shafts fitted to the 803cc/948cc Gearbox:-
2A3303............early
2A3357............mid term
22A198............late

Why the three I do not know other than they are all slightly different in finished dimensions/style.

The selector rod casting number 2A3348 (pictured above) does not appear in the 803cc/948cc BMC parts list but 2A3347 does and is listed as fork rod selector 3rd/4th gear. Possible BMC one number out allocation again????
Phil