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tips, technology, tools and techniques related to vehicle driveline components

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murray.arnold
murray forbes-arnold
croatia
(16 posts)

Registered:
09/13/2018 01:25AM

Main British Car:
1973 MGB GT ROVER 3.5 V8

KICK DOWN OPERATION
Posted by: murray.arnold
Date: September 16, 2018 02:29AM

Morning. I am here again with more questions as I have little to no experience with a V8 and automatic transmissions. I have had a v8 with 3 speed auto for 6 years. The kick down never worked. As I do so few miles this never concerned me. But I have just done a 4 barrel holley conversion and now want everything working. I think I have found the kick down cable. I have to assume this was attached to the SU carbs but maybe the carb linkage or gearbox never worked. photo attached.

Does the linkage from the carb pull on the cabe and do something in the gearbox or..... I would like to know how it all works.
I don't know what I need for the carb to attach the cable to. Photo of carb attached. (I know its on back to front. I will turn it)


IMG-20180915-WA0023.jpg
KICK DOWN CABLE.jpg



Edited 1 time(s). Last edit at 09/16/2018 07:56AM by murray.arnold.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5625 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: KICK DOWN OPERATION
Posted by: BlownMGB-V8
Date: September 16, 2018 11:16PM

Depends on the transmission.
Determine what it is and than do a search for "kickdown linkage" and the transmission model. Here is a thread on the BW35

//forum.sunbeamalpine.org/index.php?threads/bw35-kickdown-cable.18689/

Jim


murray.arnold
murray forbes-arnold
croatia
(16 posts)

Registered:
09/13/2018 01:25AM

Main British Car:
1973 MGB GT ROVER 3.5 V8

Re: KICK DOWN OPERATION
Posted by: murray.arnold
Date: September 17, 2018 05:03AM

thanks Jim. I can only assume that its a Borg box. I have no way right now of knowing.
Having just read the link it pulls the cable leading to the box and opens a valve. So I will now try and buy a new cable and new carb linkage parts, turn the carb and set it all up. Fingers crossed.



Edited 1 time(s). Last edit at 09/17/2018 05:16AM by murray.arnold.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5625 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: KICK DOWN OPERATION
Posted by: BlownMGB-V8
Date: September 17, 2018 11:17AM

That's what I would do.

For identification read these threads and/or do a search for "identification" and BW35 or whatever you suspect it could be.

[www.ozfalcon.com.au]

[www.p6club.com]

The linkage itself is very simple. If the cable is damaged you will have to remove the pan to change it but that will allow you to inspect the piston while you adjust the linkage. Again, a search will bring up instructions, and maybe a video. Note also the pan gasket can often be used to identify automatics. Do a search for "BW35 pan".

Jim


murray.arnold
murray forbes-arnold
croatia
(16 posts)

Registered:
09/13/2018 01:25AM

Main British Car:
1973 MGB GT ROVER 3.5 V8

Re: KICK DOWN OPERATION
Posted by: murray.arnold
Date: September 18, 2018 12:55AM

Thanks again Jim. Your a fountain of knowledge. Much appreciated.

I have just tread that the later type 65 box has the dipstick/filler pipe on the left. As mine does which would make mine a BW65 and not a 35



Edited 1 time(s). Last edit at 09/18/2018 01:11AM by murray.arnold.


88v8
Ivor Duarte
Gloucestershire UK
(607 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: KICK DOWN OPERATION
Posted by: 88v8
Date: September 19, 2018 04:02PM

Here is a linkage for the BW35, 65, 66 that fits the Holley carb. [www.ebay.co.uk]
No doubt there are sellers in the US.
This is the linkage I have on my Rover V8/BW66 with Edelbrock 500.

It's important to have the kickdown connected,. It controls the operating pressure in the box, and without it the brake bands will slip and the box will burn out.
When you have the linkage installed, gradually tension the kickdown cable until the change at mid throttle is fairly hard, then take it to a trans shop where they can measure the pressure in the box and set it up properly. Assume you have a shop manual for something like the Rover SD1 where it will give the correct operating pressures.

If the box has been slipping due to no kickdown, all is not lost as you can adjust the brake bands, like this [jag-lovers.org] You need a small torque wrench that reads in in inch pounds.

Brake bands need very infrequent adjustment. 50,000 miles would not be too much.
Unless someone has run the box without the kickdown cable tsk tsk..

Ivor


murray.arnold
murray forbes-arnold
croatia
(16 posts)

Registered:
09/13/2018 01:25AM

Main British Car:
1973 MGB GT ROVER 3.5 V8

Re: KICK DOWN OPERATION
Posted by: murray.arnold
Date: September 20, 2018 12:59AM

Ivor. Great info. Thanks. I have bought the linkage. Had a good look at it and I happy with what I see. I think now I need to buy a couple of parts to properly secure the throttle cable to the carb. It cam of the first drive. I should sue the garage for this. Theses are the problems I face working away all the time and having to trust other. I hate it as I prefer sorting such issues myself.

As for the gearbox operation. Wow, I never knew this could be an issue. The kick down has never operated in the car. But there is no slip or anything. So maybe it was always there but the carb end on the SUs never pulled on it. I really don't know.

By the way, does the gearbox have a breather pipe coming up in the engine bay as I have a spare pipe that I have no idea of it purpose.

Jim and Ivor. Thanks for all this. But looks like the gear box adjustment is all on myself. Trans shop in Croatia, ha ha, I will be lucky.



88v8
Ivor Duarte
Gloucestershire UK
(607 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: KICK DOWN OPERATION
Posted by: 88v8
Date: September 20, 2018 05:05AM

Running any unusual car in Croatia, I imagine that takes some doing.

Breather, I'd have said not, but this forum post suggests otherwise [www.rodsnsods.co.uk] and here's confirmation [classicroverforum.net]
We live and learn. No breather on my BW66, but I shall be looking now to see if there should be..

If the SUs were on an original auto manifold, the kickdown was part of the linkage. If they came from a manual car, that part could have been missing. It is possible to crimp the kickdown cable so there is some tension on it, which makes it sort of alright but gives unnecessarily heavy shifts at low throttle and insufficient band tension aot WOT. I see quite a few cases where a 4bblhad been put on a Rover V8 but the kickdown not connected, people sort of think it's an optional refinement..

That linkage, I recall when I was fitting it - it goes on the back of the n/s cylinder head - there was an issue with the casting not sitting flat. Can't recall whether I had to use a couple of washers as spacers or whether I just filed it to fit. Anyway, watch for it sitting down OK. Wish I'd taken pics at the time, it's all sitting behind riveted access panels.

When it stops raining - a phrase I haven't used much this year - I'll see if I can get a pic from the engine bay.

Ivor


murray.arnold
murray forbes-arnold
croatia
(16 posts)

Registered:
09/13/2018 01:25AM

Main British Car:
1973 MGB GT ROVER 3.5 V8

Re: KICK DOWN OPERATION
Posted by: murray.arnold
Date: September 20, 2018 06:51AM

thanks Ivor. All new ground for me. and all this auto box stuff is an eye opener. I have been a manual box all my life. Not that I ever ventured inside one of them either. But you now talking about stuff I had absolutely no idea about.

I now look forward to going home and sorting all this out. I think the tension on the kick down cable however will be a bit of trial and error.


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