Auto gearboxes in the S Type.

[cass3958]

Re: You Tube review of 1965 S Type
• RortPost by John Quilter » Sat Oct 24, 2020 1:18 am
He also mentions that the gearbox did not start in 1st gear. Weren't there some early Borg Warner gearboxes that only started in 1st if you had the lever in a certain position? I think some similar US Ford units did this and the Ford unit was based on the BW unit as I recall. Surprised he did not demonstrate the intermediate hold switch which is unique to Jaguars.
1965 3.8S MOD,


cass3958
Re: You Tube review of 1965 S Type
• EditPost by cass3958 » Sat Oct 24, 2020 10:03 am
1965 should have been the DG250 box which as you said would have the intermediate hold switch. The gearing was P N D L R which was for Park, Neutral, Drive, Low and Reverse. Drive started in 1st and went up through 2nd and 3rd. Low stayed in First and did not exceed 45 mph. The Intermediate speed hold allowed you to hold the gear you were in and worked in all gears. In 3rd it would shift down to 2nd and hold second until switched off and likewise in 2nd it would shift down to 1st and hold until switched off. Similar to the kickdown you get when depressing your foot hard on the accelerator but it would then hold the gear.
On the BW35 box you have P N R D 2 1 for Park, Neutral, Reverse, Drive then 2nd and 1st gear. On my gearbox, which is not the original and was replaced for another BW35 box many years ago, although I have the D, 2 and 1 on the dash display my car only does Drive and 1st. Not sure if this is correct as there are only two slots in the gear lever to allow this and if the gearbox had been changed for possibly a BW35 from a Rover ? they would not have changed the slots or the dash display. If anyone else has a 67/68 and can tell me which gears they have in their BW35 I would be interested.

So in answer to the delemour of him not getting first there is nothing to make the 1965 car with a DG250 gearbox go straight to second and stay there from a standing start unless he had the speed hold switch on but then the car would not change in to third. Unless someone else knows different.
Rob.C. P1B8973BW



NigelW
Re: You Tube review of 1965 S Type
• RepoPost by NigelW » Tue Oct 27, 2020 5:36 pm
When I got my car it had the DG gearbox (before I swapped it for a man o/d box) and it would hold 1st gear when the leaver was in the low position and held 2nd gear when the speed hold was switched on, it didn't hold third gear and the switch had no effect holding first gear. I don't know if this was correct or if my box faulty but it had to go - awful fuel wasting/power sapping/leaking contraption.
1964 Jaguar 3.8 S Type 1B50442BW (since 1976)



Glyn Ruck
Re: You Tube review of 1965 S Type
• ReportPost by Glyn Ruck » Wed Oct 28, 2020 12:26 am
It was only from the BW Model 8 gearbox fitted to the 420, Sovereign etc that you could lock out first gear & the car would pull away in second gear & become effectively a 2 speed auto & change up to 3rd automatically. It was capable of substantial speed in 2nd & great for overtaking on the open road. Also stopped a lot of hunting around in traffic. Of course it took the edge off initial acceleration but worked well for the time.
1965 Jaguar 3.8 S Type, Sync4, OD, PAS, BRG/Biscuit on chrome wires.
A1B56966DN



John Quilter
Re: You Tube review of 1965 S Type
Post by John Quilter » Wed Oct 28, 2020 4:12 am
So did any late S Types get the Model 8 along with the 420? They were made simultaneously. Maybe that is what the video car had??
1965 3.8S MOD



cass3958
Re: You Tube review of 1965 S Type
• EdiPost by cass3958 » Wed Oct 28, 2020 11:16 am
My late S Type built September 1967 has the BW35 and as far as I am aware only the DG250 and BW35 boxes were used in the S Type. The 420 which started production in 1966 had the Model 8 gearbox, maybe the gearing was better suited to the larger 4.2 engine.
Rob.C. P1B8973BW



Glyn Ruck
Re: You Tube review of 1965 S Type
• RepPost by Glyn Ruck » Wed Oct 28, 2020 12:41 pm
John Quilter wrote: ↑
Wed Oct 28, 2020 4:12 am
So did any late S Types get the Model 8 along with the 420? They were made simultaneously. Maybe that is what the video car had??
My info is no S Types were fitted with the Model 8. The Model 8 was fitted to 420's etc. because the 4.2 engine produced over the torque limit of the BW35
1965 Jaguar 3.8 S Type,
A1B56966DN


David Reilly
Re: You Tube review of 1965 S Type
Post by David Reilly » Wed Oct 28, 2020 11:14 pm
One of the changes that was not covered in Production Changes, Final in Newsletter Vol. 6. No. 6, was the change of Automatic transmissions from the American company Borg Warner's Type 35 unit to the more robust Model 8, being used in the 4.2-litre MkXs and was then to be installed in automatic 420s.
The Type 35, developed, in the 1950s, specifically for engines of less than 200 cubic inches engine displacement and less than 140 hp. As the Type 35 became popular with European automobile producers, production was transferred, in 1960, to the Borg-Warner plant at Letchworth in Great Britain, It was used by Jaguar initially in the Mk2, then in the 'S'-type, and finally in the 2.8-litre XJ6.
The initial automatic gearbox, for the 'S'-type, was Part No. C.17705, Automatic Transmission (Model DG) (J.20-0047). I was fitted to chassis numbers from:
rhd lhd
3.4 litre 1B1001 - 1B3029 1B25001 - 1B25434
3.8 litre 1B50001 - 1B53219 1B75001 - 1B77227
There was a mid-produiction change to Part No. C.25615 Automatic Transmission (Model DG) (20-00411) which aslso used a new Convertyer Assembly Part No. C. 23447. It could also be used as a replacement for the earlier Converter Part No. C.17085. This change was made for chassis numbers:
rhd lhd
3.4 litre 1B3030 - 1B8444 1B25435 - 1B26240
3.8 litre 1B53220 - 1B59528 1B77228 - 80287
The final change to the Model 8 Part No. C.26840, Transmission unit Assembly complete with Converter Unit (AS1-35FG( (35FG-509) at chassis numbers:
rhd lhd
3.4 litre 1B8445 1B26241
3.8 litre 1B59529 1B80288
This indicates that that only220 rhd 3.4-ltre, 130 lhd 3.4-litrwe, 188 rhd 3.8-litre and 130 lhd 3.8-litre 'S'-types were fitted with the later Borg Warner Model 8 automatic gearbox.

Borg Warner says about the Model 35's operation, "The M-35 has three forward and one reverse gears. The selector lever varies depending on years and car models the transmission is used in. All models follow a quadrant which has six stations. Early models have two drive positions marked with a "2" and a "1" (P-R-N-D2-D1-L; Park, Reverse, Neutral, D2, D1 and Lock). These models start off in Second gear when in the D2 position. This is useful for economy in relatively flat terrain and for starting on slippery surfaces (wet mud, snow, ice, etc.). When placed in the D1 position the transmission shifts through all three forward gears. In "Lock" the transmission can be locked to prevent upward gear changes and will provide maximum engine braking in 1st gear and moderate engine braking in 2nd gear. By selecting L from stationary, or before an upward gear change into 2nd gear, the transmission will become locked in 1st gear. By selecting L from D2 or D1 while in 2nd gear, the transmission will become locked in 2nd gear or from D2 or D1 when cruising below 55 m.p.h (88 k.p.h.) will effect an immediate downward change and lock in 2nd gear. In both these instances, the transmission will automatically change down into 1st gear when the car speed drops below 5 m.p.h. (8 k.p.h.). Should 1st gear be required earlier, reduce the car speed to below 30 m.p.h. (48 k.p.h.) and effect a "kick-down" gear change. Many people assume they have a two speed transmission because they expect the first Drive position (D2) to shift through all three gears as all automatic transmissions have done since 1968. Some vehicles had the same system without the D1 and D2, instead just having D, and only 5 stations on the quadrant."
Cheers
David



cass3958
Re: You Tube review of 1965 S Type
Post by cass3958 » Thu Oct 29, 2020 12:26 am
Very interesting so I have a couple of questions then David.

My S Type is P1B8973BW which comes within your chassis numbers being fitted with the Model 8.
If the Gearbox number starts with FG as in my car it is FG1804 would that indicate my car was fitted with the Model 8 gearbox?

Secondly my shifter screen has PRND21 (P park, R reverse, N neutral, D drive, 2, 1) but I think I only have D and 1 in reality in the box. When I go into D I have all three gears in order. 1 stays in first but I do not think I have anything in between for holding 2nd?
Rob.C. P1B8973BW
1968 S Type 3.4 Auto. Old English White.


Re: You Tube review of 1965 S Type
Post by Glyn Ruck » Thu Oct 29, 2020 1:03 am
Very interesting David. The scribes I read have it wrong in that case or I have misunderstood. I apologise for misleading people. Thank you for the correction. Certainly no S Types with the Model 8 were ever built in South Africa & your number sequence confirms that.


What James Taylor had to say regarding the matter ~ S Type to 420. I did not think I was going mad.

BW Model 8.JPG (84.69 KiB) Viewed 26 times
1965 Jaguar 3.8 S Type,
A1B56966DN

Glyn Ruck
Re: You Tube review of 1965 S Type
• ReportPost by Glyn Ruck » Thu Oct 29, 2020 1:53 am
Rob ~ how does this gel with your actual BW35? Presume you have your original steering column & selector. Obviously he means late MkX & 420G along with the 420. It would seem your car was originally fitted with a Model 8 ??? Other than standardisation in manufacture the 3,4 would not require a Model 8.
1965 Jaguar 3.8 S Type,
A1B56966DN

David Reilly
Re: You Tube review of 1965 S Type
• ReporPost by David Reilly » Thu Oct 29, 2020 1:56 am
Rob,
Yes.
All of the automatics on the Register, with chassis number in the Model 8 range, have gearbox numbers beginning 'FG'.

[cass3958]

OK I am puzzled now for a couple of reasons.
My original gearbox was serial number FG1804 but at some point in its early life it had a categorical failure. So much so that when I was rebuilding the car I found holes that had been punched into the gearbox tunnel under the carpet where the transmission had exploded. So FG1804 was ditched and FG1107 was put in its place. This number but not correlate with other S Type gearbox numbers starting with FG so must have come from another make car (BW gearboxes were used across a lot of British Leyland cars, Rover and Triumph) or was brand new. Either way it was a direct transfer of one FG box for another. There does not appear to be any alteration of the gear selector set up.

So we have talked above about the gear selector so I have just been out for a drive to check mine. It is P R N D 2 1 on mine. P R and N are as is. D I get drive in 1st going up through the gears to 3rd. There does not appear to be anything happening when I move the selector to 2. It is the same gate and the car does not change gear or alter from 1st going up to 3rd. It does not select 2nd from start or hold second gear. To select 1 there is a gate and if 1 is selected it changes down to 1st and holds first even if you rev the nuts off it. So what is supposed to happen when 2 is selected and why does nothing happen in my box?

David has stated that all gear boxes with the serial number beginning with FG are actually Model 8 gear boxes, still made by Borg Warner. So I got my car up on the ramp to check the serial number on my gearbox which I can confirm is FG1107. The plate is very difficult to see but I managed to get a photo of it by shoving my phone up between the exhaust and chassis leg. The plate states " Automatic Model 35 serial number FG1107 ". So the next question is; Was the model 8 a variation of the BW35 or are our facts here all to cock and FG was also used on the BW35? How is a Model 8 Gearbox plated up for identification?

[Glyn Ruck]

Rob has transferred my contributions above as possible but this did not come over.

Very interesting David. The scribes I read have it wrong in that case or I have misunderstood. I apologise for misleading people. Thank you for the correction. Certainly no S Types with the Model 8 were ever built in South Africa & your number sequence confirms that. [Only fitted from SA built 420's]


What James Taylor had to say regarding the matter ~ S Type to 420. I did not think I was going mad.

BW Model 8.JPG (84.69 KiB) Viewed 2608 times

Obviously he means late MkX & 420G along with the 420.

[Glyn Ruck]

Wow Rob. That's interesting & blows the FG prefix theory.

Also regarding your column & shifter. Just because a manufacturer says their box is capable of doing something does not mean that the OEM (Jaguar) used it in that fashion. I guess the same could be said for Jaguar only using the Overdrive on top gear & inhibiting it from other forward gears. Other manufacturers did differently.

Another thing that comes to mind is ~ disregarding the shifter. Did the BW35 use the same linkage as the Model 8?

I find all this very interesting as I have never owned an Auto so have only casually read what has been said about them & driven a few.

I believe the Taylor torque comments to be accurate. That is just common sense.



Of course police S types had a very restricted shifter.

Police S Types..JPG (175.56 KiB) Viewed 2602 times

[cass3958]

It would be interesting to know what gearbox the Police cars had in them. Is it a gearbox with just reverse neutral and drive or is it the shifter that has been adapted so that only reverse and drive can be selected?

We need some input from someone else with a late S Type that might have been fitted with a Model 8 box to see if they have the same selection as I have and whether they have a different identification tag with Model 8 rather than Model 35 on it? Will have to send out some emails to the owners I am in touch with to see what they have.

[Glyn Ruck]

David said in a previous post that they had a special pawl fitted that blocked the other shifter positions but I know very little about UK Police cars other than what I've read.

[cass3958]

Yes I can see how a blocked segment Pawl would work. I have an old Police colleague friend who I bumped into a month ago whilst I was out driving my S Type and he commented on the fact that when he was in the MET on the Flying Squad he used to drive the S Types so the next time I see him I will have to ask him more about his experience.

[David Reilly]

The Met, when the automatic gearbox was fitted, it had a special pawl that did not allow Park or Low to be selected. There was also no Park or Low position on the gear indicator on the steering column. The transmission had those gears internally, but they were blocked off. There was also no anti-creep feature. The reason for this is said by veteran The Met pensioners to be that drivers would put the transmission into Low and with the 4.09 differential, accelerate as fast and as long as they could when in pursuit. Without a tachometer, it was very easy to over rev resulting in blown engines. Also, arriving at the scene of crime, the driver would sometimes throw the selector into Park before the car had stopped. Soon, The Met had a collection of blown transmissions as well. It is thought that this feature was specific to The Met ‘S’-types only.

[cass3958]

David in your previous thread you stated;

Borg Warner says about the Model 35's operation, "The M-35 has three forward and one reverse gears. The selector lever varies depending on years and car models the transmission is used in. All models follow a quadrant which has six stations. Early models have two drive positions marked with a "2" and a "1" (P-R-N-D2-D1-L; Park, Reverse, Neutral, D2, D1 and Lock). These models start off in Second gear when in the D2 position. This is useful for economy in relatively flat terrain and for starting on slippery surfaces (wet mud, snow, ice, etc.). When placed in the D1 position the transmission shifts through all three forward gears. In "Lock" the transmission can be locked to prevent upward gear changes and will provide maximum engine braking in 1st gear and moderate engine braking in 2nd gear. By selecting L from stationary, or before an upward gear change into 2nd gear, the transmission will become locked in 1st gear. By selecting L from D2 or D1 while in 2nd gear, the transmission will become locked in 2nd gear or from D2 or D1 when cruising below 55 m.p.h (88 k.p.h.) will effect an immediate downward change and lock in 2nd gear. In both these instances, the transmission will automatically change down into 1st gear when the car speed drops below 5 m.p.h. (8 k.p.h.). Should 1st gear be required earlier, reduce the car speed to below 30 m.p.h. (48 k.p.h.) and effect a "kick-down" gear change. Many people assume they have a two speed transmission because they expect the first Drive position (D2) to shift through all three gears as all automatic transmissions have done since 1968. Some vehicles had the same system without the D1 and D2, instead just having D, and only 5 stations on the quadrant."

Where did you come across this information as I would like to read it in full if possible.

It talks about the M35 and that early models had the D1 and D2 settings then stated that

Some vehicles had the same system without the D1 and D2, instead just having D, and only 5 stations on the quadrant

but there is no individual recognition of the Model 8 only referring to it as M35 and early or late.

In the first part where you quote the chassis numbers you has stated the Auto gearbox changes were (Model DG) (J.20-0047) to (Model DG) (20-00411) then final change to the Model 8. There is not mention of the BW35 in this line of gearboxes. Is this a typo and the middle one should have been the BW35?

I am also intrigued as to why my identification plate has the FG letters which you state is a Model 8 box but it also has model 35 on the same plate with nothing referring to Model 8. Is the Model 8 just a variant of the BW Type 35 box?

[cass3958]

OK I think I have found the article that David refered to. https://www.wikiwand.com/en/Borg-Warner_35_transmission

Basically the BW35 was the first aluminium housed gearbox that Borg Warner produced. The 3 stands for 3 forward gears. The second number is the model so they made a BW35 first built in 1950s BW36 1965 and a BW37 1967 and the higher the number the more torque it would take. The BW35 gearbox in my S type is the aluminum cased version and there is no mention of serial numbers ie FG actually meaning anything.
It states

The M-35 case has provisions to be drilled for an external cooler, but no U.S. models used an external cooler and do not have the internal provisions to mount one. There may be European models that were equipped with external coolers.

My BW35 has an external oil cooler as standard with pipes running from the gearbox to the underside of the radiator which has a built in oil cooler section.

The Borg Warner Model 8 gearbox is actually older than the BW35 and has a cast iron case making it stronger so to be used with higher CC and Torque engines.