BW35 and BW45 Automatic Gearbox tech

[JoKer]

sweet, keep in touch : going to Weirs farm finally this weekend to search for the one dumped down the bank

[azza1600]

Share Ross, we only 1.5h drive away an I travel there for work......FREE GAS!!!

[oldschool]

I don't know where in Wairoa Aaron...I do know there's two Avengers together...so twice as easy to find...lol

[JoKer]

I just did a happy dance : missing bits turned up

I know a useless update but really boring around here!

catchup with Pete and farm raid is still on for this weekend, was talk of building a track with bulldozer to get gear out so sounds like there could be a bit of scrap down this "bank"

I know of another Auto Blue one in a Shed in Woodville too, figure try and use what I got 1st : maybe buy a complete wreck if I have too

[JoKer]

this BW45 appreciation thread just popped up on oldschool.co.nz


http://oldschool.co.nz/2011/forum/index.php?/topic/53121-borg-warner-model-45-auto-one-for-the-hillmanites/

locost_bryan, on 10 Jun 2016 - 10:00 AM, said:
Stumbled across a 1972 article in Autosport magazine about Borg Warner's then-new English/Welsh 4-speed auto. http://www.motorsportmagazine.com/archive/page/october-1972/58

A new Borg-Warner automatic gearbox.—We went down to Port Talbot, braving the distinct possibility of getting irretrievably lost in Swansea on the way home, to see the impressive factory which Borg-Warner have erected on the new Kenfig Industrial Estate just off the A48 (M) road, where they are introducing new methods of production of their automatic transmissions in a fine new building of some one-million square foot floor space.

The main purpose of this move to Wales is manufacture of the new Type 45 four-speed Borg-Warner automatic gearbox, for cars of up to 2-litres, which will eventually supersede the well-known Type 35 three-speed box. We were able to sample the Type 45 transmission in a fuel-injection Volvo 144 which, together with a 1.3-litre Morris Marina, are being used for development and demonstration purposes, and the smoothness of the changes in this closer-ratio gearbox was most apparent. It marks a notable step forward in using plate clutches instead of the difficult to keep in adjustment band brakes of the earlier gearbox and it is significant that pressings replace castings for many of its components. The design, it is pleasing to note, stemmed from this country rather than from America and the new Type 45 box will also be made as a three-speed Type 55, which Toyota are using at present, the casing being sent to them from the Welsh factory.

The production methods at this impressively spacious factory, where 1,500 operatives work, a number to be doubled when the full production of 1,000 Type 45 and 500 Type 55 gearboxes per day is achieved, are most interesting. For instance, there will be an 83-stage transfer machine, supplied by Lamb of Ontario, for machining the aluminium gearbox casings, which needs but three operatives to oversee it. Two 1,000-ton Wilkie & Mitchell presses stamp out clutch cylinders, to a ready-to-use state, with no subsequent machining involved. There are nine stations per press. In contrast to this automation, women operatives fit the rotor blades by hand. Components will be conveyed about the factory on roller-coasters, and J-pattern travelling jigs will facilitate assembly, right up to the dispatch stage. Completed gearboxes are all tested on A. T. & T. dynamometers, having been balanced electronically while revolving at 1,100 r.p.m., their heavy-point marked with a blue spot for the guidance of the car manufacturer fitting the box to his engine.

The gear assemblies are electron-beam welded, each being completed in 4? seconds, the weld being made in a vacuum, using Scieky apparatus, which obviates any distortion or interference with the heat treatment of the gear pressings. Before welding, the components pass through a Raydne washing vat.


Even a brief inspection of the new Borg-Warner plant shows that the company plans a big expansion. Apart from the new gearbox, it supplies BMW, Saab and Citroen with automatic transmissions, while the applications of the Type 35 B-W box to British cars are too well known to need enumeration. B-W claim to have well over 5-million units in use and to serve more than 80 manufacturers in eight countries. They are seeking customers for the new Type 45 transmission, which has ratios of 3:1, 1.94:1, 1.35:1 and direct-drive, against those of 2.39:1, 1.45:1 and direct drive of the Type 35 box. Aluminium is now used for all automatic gearboxes intended for cars of up to 4-litres, although cast-iron casings are found in the XJ6 and XJ12 Jaguar transmissions.

Curious to know what changes Rootes Group made when they changed from the 3-speed Model 35 to the 4-speed Model 45 in the Hunter and Avenger.  Was it a straight swap, using the same bellhousing, torque converter, gearbox mounts, and tail shaft?  Or were all these components unique to the 45?

Often wondered why this auto wasn't adopted by other manufacturers, especially during the fuel crisis of the mid-70s, as it would seem that the lower first gear ratio (3.1 vs 2.39) would have allowed a taller diff ratio to be used.  Or did it have a different torque converter that had a lower multiplication factor, requiring a lower first gear to achieve the same acceleration?

[oldschool]

The BW45 wasn't popular as weaker than the BW35 which could handle 6 cylinder Valiant Hemis and V8 Stags! Also people complained that they changed down from top to 3rd on the slightest incline, whereas the BW35 would hold top for longer.
Very few parts are shared between the BW35 and BW45. They have different front flanges, so use different bell housings and have different gear linkages too, BW35 is cable, BW45 is rod. The tailshaft spline and gearbox mount are the same.
I have a BW45 for sale on TradeMe...made in the UK as they said!

[JoKer]

Speedo drive woes Help

cable is complete from top to bottom & the speedo flicks over when you manually drive it with a screw driver

what the fix? / BW45 sender unit?

sent it down to garage to get them to check on their hoist

[JoKer]

So I had a loud bang and loss of drive this morning at about 80kph, speedo went to zero, pulled over & stopped

Loud clunk into drive and RND etc "Hoping diff" as it did have a bit of a whine BUT the no speedo thing worries me heaps (as in no drive out the rear of the box tho I did not rev it)

Waiting for tow truck to turn up with car to check it out but noticed Ross had stopped listing the BW45 he had (waiting for reply to my txt) and I have oodles of spare manuals but really REALLY wanna keep it Auto just for the spite of it

anyone else have eyes on a spare spare Box? Mine might be salvageable this time (different failure to my OEM one i have in bits in the shed)

any reason I couldn't use a "Avenger BW35" in place of the 45? Triumph 35's have proven to be different bolt patterns