MGB rear tube shocks for MGB

[mgbmedic]

Hello everybody! It's been a long while since I've posted. I'm not much of a "sit in front of the computer and play" kind of person. I'd rather be out working in the garage or playing in the B/GT or TR6. But, when I do have a question pertaining to my cars, I always ask first here at the BCF and then proceed armed with the knowledge gathered by those that have "been there, done that..." My question is...
Has anyone put tube shocks on the rear of a chrome bumpered B or B/Gt and not used a kit. A good friend of mine has installed a set of gas shocks intended for a Chevy S-10. He said the only modification is to turn the shock plate on the leaf springs upside down. The use of #8 bolts for shear strenth is all that's needed. He said he found the info on the internet. Has anyone seen or used this application? Thanks, Bob

 

[DrEntropy]

I've seen it done, but the geometry looked a bit "funny" to me. Two different angles on the shock, IIRC.

 

[Steve_S]

Even with a kit, the chances of seeing an improvement are unlikely. Since the suspension and chassis of the MGB was not designed for tube shocks, there is no way to mount them where they can work properly. Yes, they will function. But there will be side loads which will wear the shocks prematurely. Another major problem is that no tube shocks have ever been specifically designed for an MGB. On modern cars, extensive testing is performed to create a shock which will optimally control the car's suspension.

There are people out there who like their tube shock kits but they are heavily outnumbered by those who do not like them. And some of those who did see an improvement are comparing them to 30-year-old worn out originals. Many people don't consider the fact that the originals were still functioning after that amount of time. The same cannot be said for any tube shock! My advise is to top up the fluid in your lever shocks and spend your money elsewhere.

 

[DrEntropy]

Yep. The angles I saw would surely wear a tube shock in no time. The "kits" aren't much better. A set of lever arm units *may* need rebuilding, and if you still want more (read: stiffer) damping, there are more restrictive valves available... but the original set-up is actually very good.

 

[kennypinkerton]

There's nothing wrong with the mechanical units. Might need repacking, but then they'll last another 30 years. Plus I'd bet the unsprung weight is a lot less with the originals.

 

[DrEntropy]

"Unsprung" is at the ends, beyond (outboard of) the "sprungs". /ubbthreads/images/graemlins/jester.gif

 

[kennypinkerton]

Yeah... I actually got into the "unsprung weight" thing while racing 1/10th scale r/c cars... imagine - try to save a 1/4 gram here and there. hehehehe.

 

[tony barnhill]

I've done it before...in addition to swapping the perches left to right & vice...I straightened them just a tad.

 

[Scott_Hower]

[ QUOTE ]
Yep. The angles I saw would surely wear a tube shock in no time. The "kits" aren't much better.

[/ QUOTE ]

Angles? What angles, Doc? /ubbthreads/images/graemlins/cool.gif

I have adjustable Konis on the rear of my B (with Koni supplied brackets) and there is no off-axis side loading. The are canted forward a few degrees but they are straight up and down. If the spring is doing it's job to locate the axle properly, there should not be any side loading on a tube stock, just vertical loading.

According to the Koni catalog I have, they are specific to MGB/MGBGT with unique valving (not a Gremlin shock that just happened to be the right length).

 

[artmck]

I bought a kit on ebay for well under $100.00 that has been fine. I think the guy makes them, so check there again. Can't beat the price. My main objective was to replace bad levers for cheap since I have other plans for the rear anyway and they have been good at least for the 6 months I have had them.

 

[DrEntropy]

Angles I refer to were from swappin' brackets side-to-side and inverting them. NOT the same as acquiring a Koni kit, Scott. That I certainly ain't disputing.

The "kits" I'm talking about are a set of 'blue' shocks and some bolts, with a couple brackets and spacers... The Koni setups are as expensive as rebuilding/replacing lever arm units, maybe more IIRC.

 

[Steve_S]

[ QUOTE ]
The Koni setups are as expensive as rebuilding/replacing lever arm units, maybe more IIRC.

[/ QUOTE ]
And tube shocks typically need to be replaced after a few years... sometimes less if driven hard. Lever shocks can easily last 25 years. I honestly can't think of a good reason to use tube shocks on a stock suspension. If you need adjustable stiffness you can get original type lever shocks with remote adjusters.

 

[xsteamer]

I installed new rear springs and converted to tube shocks. You can go to this link for info: https://www.mgexperience.net/article/rear-shock.html
The only problems I had were I had to use a reciprocating saw to cut off the front leaf spring bolts. I have heard since I did it that you do not require rebound straps with tube shocks. Unfortunately I had already bought and installed new straps so I left them on anyway. I don't think there is any adverse effects?

 

[mgbmedic]

well then...would the tube shocks increase the height of the rear end?

 

[Steve_S]

[ QUOTE ]
would the tube shocks increase the height of the rear end?

[/ QUOTE ]
Shocks themselves should make no difference in ride height. The springs and suspension components do that.

[ QUOTE ]
I have heard since I did it that you do not require rebound straps with tube shocks.

[/ QUOTE ]
The rebound strap is required regardless of the type of shock used. They prevent the axle from falling too far away from the car which can force a shock past it's maximum extension and break it. Other problems are damaging springs, tearing off brake lines, damaging exhaust pipes, etc.

 

[Bret]

I’ve been running the same tube shocks for a little over 4 years now without any problems and still have the same ride feel as it did when I first installed the conversion kit. Granted you can rebuild the lever shocks but in my case one of my levers was completely toasted and invaluable as a core. Cracked & bent lever that I can only guess was thanks to some spirited driving by the PO. Anyway for about the same price as rebuilding the one good lever shock I purchased a tube shock kit. Should the tube shocks fail – I can go down to any parts store to get them.

Now one thing I did notice that I liked about the tube shocks is that without any other upgrades I actually liked the feel and seemed to have less lateral leaning. When I added some new lowering coil & leaf springs and poly bushings front & rear the ride was even more taunt. Perhaps my setup would be a bit too stiff for most folks but I like it.

 

[Scott_Hower]

[ QUOTE ]
I honestly can't think of a good reason to use tube shocks on a stock suspension. If you need adjustable stiffness you can get original type lever shocks with remote adjusters.

[/ QUOTE ]

Steve - you are welcome to your opinion and the purist in me wants to believe you; it really does. But the realist disagrees.

They may have been great (and cheap) technology at the time, but I still maintain that modern shock valving technology is superior to levers. Even Morgan now use Konis. Technology has simply moved on.

And no one, short of Don Hayter or Roy Brocklehurst, are going to convince me otherwise. /ubbthreads/images/graemlins/jester.gif

 

[Steve_S]

[ QUOTE ]
They may have been great (and cheap) technology at the time........Even Morgan now use Konis.

[/ QUOTE ]
Lever shocks were cheaper than tube shocks at the time these cars were new, which is why the car was designed for them. Today tube shocks are far cheaper and work better with modern suspension designs. They also take up less space than other types of shocks would.

In my opinion, unless you're talking about progressive valving, a shock is a shock. It has a small valve which meters the fluid forced through it, which in turn controls compression and rebound rate. The trick is to mount the shock with the proper geometry and match the damping action to the vehicle's road handling characteristics. There is good reason why many racing MGBs retain their lever shocks! They are simple and durable, and a perfect match for the car in both fit and function. With a completely redesigned suspension I would undoubtedly prefer tube shocks!

BTW, has anyone else noticed that Ferrari recently began using a non-tube shock in their F1 cars? In fact, the design is nearly identical to the pre-war MG Girling Luvax lever shocks used in MG R-Types!

 

[kennypinkerton]

makes sense

 

[PAUL161]

Being into antique cars as I was a few years ago, I know that most old cars used some type of lever shock. Also most of them were ajustable by turning a valve located somewhere on the shock. The old Fords were located on the end of the main shaft. These lever shocks worked very well. We used them in tandem on race cars in the 60s. The reason most manufactures went to the "Tube type" shocks was because they were cheaper to manufacture in the sense that they could adapt someone elses shock to work on different vehicles and they could be made in various lengths without changing the basic design. From there the technoligy took off and the tube type shocks took over. I would venture to say that today, because of making castings and the extra labor involved, it would probably cost three to four times as much to manufacture a lever shock than a tube one.