TR2/3/3A 1956 TR3 with Lockheed Drums to Disc Questions

[trmjr1]

I have a 1956 TR3 with Lockheed drums all the way around. I'm not too familiar with the early TR's - I was an MG and Spitfire guy in the 80's.

I have been researching and reading about the short comings of not only the Lockheed brakes but also the Lockheed rear end housing and axles. I have a line on a later Girling rear end assembly (1960?) and complete front disc brake set up reportedly for a TR 3 or 4 with upper and lower control arms.

I've always been an originality guy, so I'll keep the original set up, but for safety, performance and convenience, I'd like to have the Girling rear end and front disc brakes.

What do I need to look out for?

Thanks,

Tom

 

[TR3driver]

The main hassle will be buying soft lines that mate with the Lockheed fittings on one end, and the Girling on the other. Those 60 year old hard lines are a bit dubious anyway IMO, so you might consider re-doing the hard lines with the Girling ends at the front wheels & rear axle. (Which I think means you'll also need the Girling 5-way connector, maybe you can get that with the brake setup.)

There were tabs added to the frame in front, for where the hard line meets the soft line, so that may be a problem as well.

Otherwise, I think everything will bolt up, including the handbrake. You might want to look at the front suspension though; if it's the later TR4 version with 3 degrees of caster you can expect more steering effort. But the caliper mounts will fit the old vertical links, so you can keep the old suspension if you want. Don't get the trunnions mixed up though, the 3 degree suspension uses a different trunnion on each side and it's easy to miss the angle on casual inspection.

You'll need to keep an eye on the fluid level in the MC (if you keep the Lockheed MC). The front discs normally take a larger reservoir because the pistons stay out farther as the pads wear. But they don't wear very fast, so not a big deal.

 

[trmjr1]

Thanks for the reply. That's good to know about the different lower suspension geometry. The seller said they are TR3/4 disc brakes and to use my lowers, so now makes sense. I plan to convert to the Girling dual brake and clutch master cylinders and run new hard and soft lines. Good to know about the tabs on the frame - will have to plan for that.

 

[CJD]

The lines will be a bit of a pain. The Lockheed goes from the MC down to the main distribution block on the left front wheel hose connection. The brake light switch is on this left side block. From there it goes under the motor to a secondary distribution block off the right front hose connection that sends a line to the rear. All flare nuts are 3/8"x20.

The Girling goes from the MC to the right side frame, where a separate distribution block sends lines to the front left/right, and back to the diff. All flare nuts for the Girling are 3/8"x24. The brake switch is on the 5 way block on the right.

So...every hose and distribution block from the new brakes will need 24 pitch flare nuts for the lines going into them. Any distribution block you retain from the Lockheed system will take 20 pitch flare nuts. Short of obtainingthe entire Girling system including hard lines, you will have a lot of fun trying to plan out your routing for hard lines and brake light wiring.

Aside from that...the mechanicals are a simple bolt and go deal. I wouldn't mess with changing the vertical links. Just unbolt the front back plates and bolt the disc adapter right to your current vertical link.

 

[TR3driver]

Thanks for the reply. That's good to know about the different lower suspension geometry. The seller said they are TR3/4 disc brakes and to use my lowers, so now makes sense. I plan to convert to the Girling dual brake and clutch master cylinders and run new hard and soft lines. Good to know about the tabs on the frame - will have to plan for that.

Don't forget, the pedals changed too.

FWIW I converted my TR3 to use a mechanically operated brake light switch. Had just too much trouble on the previous 3A with the hydraulic version failing (which may have had something to do with the DOT 5 brake fluid). I also wired it with a separate "always hot" fuse, so that the brake lights work even with the key off, and even if the wiper motor (for example) blows the fuse.


I also added some relays to make the corner lamps do triple duty as brake lights as well as turn & tail. No changes to the original harness (or new wires to the rear), the relays are hidden under the dash and connect to the original harness by the LH horn.

 

[TimK1955tr2]

Have you tried driving a properly sorted and set-up Lockheed drum system?

I have a later TR2 that I think is fine with all original parts but completely rebuild and adjusted. Yes, it can pull a bit if not adjustment is not kept up but I have found it has plenty of progressive stopping power with no noticeable fade.

I also have a stock Lockheed axle and haven't had any problems. I do not baby my car at all but also don't beat on it like an 18yo would, burn-outs, etc...

All things being equal, I would of course choose the disc brakes and Girling axle if only for ease of use and parts availability. I did snatch up an additional Lockheed rear axle on Ebay a few years ago to be on the safe side for spares.

But it seems like a lot of effort and money unless you are doing full-on mountain rallying...?

I know my thoughts run counter to some of the most knowledgeable people on this forum but wanted to give my experience... Tim

 

[mgedit]

Like Tim, I have not experienced any issues with braking on my 56 TR3 with drums. No doubt discs are better, but drums seem OK for general driving. Same seems true of the Lockheed rear axles. Cheers, Mike

 

[trmjr1]

Great information. I was originally planning to keep the Lockheed drum brakes but when the opportunity to purchase a complete used front disc brake set up as well as a Girling rear end presented itself, I decided to change course.

The car is primarily for my wife but I will drive it also. I tend to drive my cars pretty aggressively (it's a sports car, after all) and remember how much trouble I had keeping axles and bearings in my Spitfire when I was auto crossing it. Figure better safe than sorry and if I've got to rebuild everything anyway (car sat for 35+ years), might as well go with disc brakes.

I will definitely run new lines and distribution blocks.

Thanks,

Tom

 

[TR3driver]

There might well have been some problem that never got detected/fixed; but I was far from happy with the front drum brakes on the earlier TR3 that I owned for awhile. I had a TR3A at the same time (with front discs obviously), and the difference in braking between the two cars was like night and day. Careful adjustment didn't seem to help, neither did replacing shoes, having drums turned and rebuilding the cylinders. The drums were OK out on the open road where I could always plan my stops. But here around La-La Land, panic stops are a frequent occurrence and the drums just never inspired confidence. Part of the problem was that they only pulled sometimes, and rarely in the same direction as the last time. If you got close to the limit on braking, often one front wheel would lock and not the other, which of course would make the car want to suddenly swap ends.

Admittedly, I do drive hard on occasion; harder actually than when I was 18. My current 56 (with original Girling brakes) has been out on the track exactly once : first in class at a VTR autocross. Same with the 3A I had before that.

I have no quarrel with those of you who are happy with your front drums; just reporting on my experience.

 

[TimK1955tr2]

I was really just throwing my 2 cents in to possibly save energy and money on a fairly large brake/axle swap if not completely warranted by future intent, that is my cheap and simple personal perspective. Also, I generally like people to experience cars restored to proper original working condition before too many judgements are made without first hand knowledge. I have fallen into trap of trying to upgrade cars too much when I should just bought a "better" car...!


Difficult to gauge what is "hard" driving, I meant that a mechanically unsympathetic daily driver could trash a car much faster than a good driver on a track.

Good luck and enjoy!!

 

[trmjr1]

Tim,

Your thoughts and opinions are greatly appreciated. I am already throwing a great deal of money at the car so once the disc brake set up and Girling rear axle became available, I figured I would go that route.

The car has probably not been driven in 35+ years. The rear brakes shoes and drums were difficult to remove - the right side shoes were oil soaked from gear oil and the master cylinder is rusted and has deep pitting. The fronts were a little better.

I have to rebuild and replace everything either way I go, so might as well do disc brakes and figured this was the place to get the true picture of what I was in for.

Thanks,

Tom

 

[TimK1955tr2]

Hi Tom,

Sounds good, I would hang on the Lockheed parts to keep the car complete... or at least get a good price for them.

You will have a fun driving experience either way, look forward to hearing about the progress!

Tim