MGExp

MGB & GT Forum

Finishing the Lowering Job

Moss Motors
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor

Finishing the Lowering Job
#1
  This topic is about my 1977 MG MGB MkIV
JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Hey, Everyone,

I have researched this here, but didn't really find an answer by someone who has done it. (Just because I didn't find it doesn't mean it isn't here, I just didn't find it.)

I purchased a 1977 MGB (My first.) April 28 and I'm sorting through a few concerns. It is believed that this car has been lowered with Moss components front and rear. (Looks great!) However, the concern is that the front lowering is by spring height only. The car essentially rides on the lower bump stop and the steering rods from the rack point up.

I know the bump stop can be modified/replaced to allow for more travel, but would exchanging the steering arms left/right and inverting them successfully allow the tie rod ends to be attached from the bottom, thereby reducing the tie rod angle in relation to the rack unit?

Again, I read a discussion of the idea, just didn't see a reported result.

Thanks!

-Justin

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
jckent Avatar
jckent Silver Member Royce Burnett
Miami, MB, Canada   CAN
I tried reversing the steering arms and tie rod ends on my car, but couldn't make it work, not enough clearance on the tie rod ends if I recall. I guess I could have tried bending them to get clearance but I chickened out. I might revisit that over the winter.

JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
In reply to # 3735725 by jckent I tried reversing the steering arms and tie rod ends on my car, but couldn't make it work, not enough clearance on the tie rod ends if I recall. I guess I could have tried bending them to get clearance but I chickened out. I might revisit that over the winter.

Thanks for the reply, Royce. Clearance on the tie rod ends against what?

I'm new at steering/suspension work, but what I see doesn't look good.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
jckent Avatar
jckent Silver Member Royce Burnett
Miami, MB, Canada   CAN
There didn't seem to be room for the tierod ends against the backing plate. The full story on my car is that it was a 74.5 RBB originally, I had found a CBB cross member from someplace and put it on, retaining the original RBB rack and pinion and I have just shimmed the angle where it bolted on to the x-member to get the the steering shaft thru the engine mount. Had to grind that hole out a bit.

I'm not sure if that was the best way to do the lowering or not, but it looks right. I would guess that the car is more twitchy due to bumpsteer than most guys would enjoy but I'm used to it. I might try to find a couple more steering arms to mess with and see if I can level the tie rods out a bit better.

JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Gotcha. Thanks for that, Royce.

There doesn't seem to be any instability in the steering, just a loss of contact on anything less than a perfect road surface. The blame for that seems to be the limited suspension travel.

The tie rod is mostly a premature wear/failure concern.

jimb Avatar
jimb Jim Brown
San Francisco Bay Area, USA   USA
1967 MG MGB
I think Lloyd has posted several times about the correct way to lower a rubber bumper B.
Here's one of his posts that may help you:

https://www.mgexp.com/phorum/read.php?1,2820250,2820250#msg-2820250

V8MGBV8 Avatar
V8MGBV8 Carl Floyd
Kinggsport, TN, USA   USA
It depends how much the front has been dropped. If it has only been dropped an inch or so with springs, you can mod the bumpstops (which you need to do anyway) & not worry about the bumpsteer.

You could also get Dave Headley's "bent" steering arms that he mods to correct bumpsteer.

Measure the distance from the center of the wheels to the bottom of the chrome strip, so we can tell where your RB B really sits.



Edited 1 time(s). Last edit at 2018-05-15 08:29 AM by V8MGBV8.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Thanks for the ride height points of reference, Carl. I have seen information about measurements when reviewing ride height specs related to springs in the Moss catalog, but did not know where to measure. I knew it wasn't 14.7 inches off the ground. (Ha!)

I will report my findings.

JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Thanks for the link, Jim. I hadn't seen that post. Probably a matter of my search terms.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
In reply to # 3735867 by jimb I think Lloyd has posted several times about the correct way to lower a rubber bumper B.
Here's one of his posts that may help you:

https://www.mgexp.com/phorum/read.php?1,2820250,2820250#msg-2820250

The last paragraph in the linked post helped my understanding of suspension geometry a ton.

Be Coming Avatar
Be Coming Kelvin Dodd
So. Calif., USA   USA
Justin.

The springs Moss recommends to lower the RBB only lower the front of the car about 1". That still allows reasonable suspension travel and no noticeable bump steer. From your description, the past owner may have installed 2" lowering springs which do reduce the travel and may cause problems with the bump stops.

Measure from the center of the wheel to the bottom of the stainless molding. A chrome bumper car should be about 14.5". A rubber bumper car should be about 15.5" both with new springs.

Kelvin.

edit: I've attached a couple of image of what the Moss 264-386 lowering springs do to the front of a 1976 MGB. The rear has the lowering blocks fitted.



Edited 1 time(s). Last edit at 2018-05-14 10:07 AM by Be Coming.


Attachments:
Lowered Side.JPG    67.6 KB
Lowered Side.JPG

Lowered Front.JPG    48.7 KB
Sign In or Register to view this photo
Peter-Sherman Avatar
Peter-Sherman Peter Sherman
Melbourne, Australia   AUS
I've lowered 2 inches via springs. I've been doing quite allot of rough old country road driving of late (taken up hiking) and that has finally got me wanting to do something about bump steer. I didn't notice it on city roads.
I bought some bent arms off dick (Dick Lueing www.mgbracing.com ). Don't just bash away at them (regular arms) in a vice, you'll work harden them. You don't want a steering arm to snap and fail . They need to be reforged, heated up orange and cooled very slowly in sand by someone who knows what they are doing.lA little under one inch, photo 1. They were not very expensive, about 60AUD the pair including shipped to my door. The shipping to Australia cost more than the arms. These, surprisingly, work out very nearly parallel to the bottom arms. photo 2. A big improvement. I think if I add some quarter or half inch spacers under the spring capture seats in the crossmember, that will get it perfect. I did try some moss chrome bumper springs, but they brought the car up 1&7/8", hopeless.
Whilst I was doing that I tried the "shift the spacer" trick on the bumpstops. Other peoples idea but I don't think anyone has posted a comparison photo. . You cut the aluminium spacer in half and move the pieces, and their bolts, up and under the upper stops. You also have to squish about half the angle out of the the bottom bend and increase the top bend to 90 degrees. It's easy enough with a vice, the metal is soft. Then get all the bolts started and tighten up. The one on the right is original. photo 3,
Out of curiosity I did also try swapping and flipping the arms to get them very nearly parallel to the ground, Flipping ordinary arms will get you about 65mm, way too much, but allowing for the bend in the bent arms takes you back 18mm. Roughly 48mm lowered. Big mistake, the angle to the bottom arms meant bump out then in. Horrible, needed a death grip on the steering wheel to control the car. I put the bent arms back on the usual sides soon as possible.

I should add, the arms are effectively slightly shorter, which changes the Akerman slightly, but that seems to suit my 6 inch width 25mm positive wheels. Used to squeal a little on tight corners, doesn't now.



Edited 2 time(s). Last edit at 2018-05-15 03:45 AM by Peter-Sherman.


Attachments:
Dicks bent arms.jpg    45.8 KB
Dicks bent arms.jpg

bent arms on usual side 2 inches lowered car.jpg    44.4 KB
Sign In or Register to view this photo
front bump stops.jpg    48.6 KB
Sign In or Register to view this photo
DPO-ing.jpg    51 KB
Sign In or Register to view this photo
V8MGBV8 Avatar
V8MGBV8 Carl Floyd
Kinggsport, TN, USA   USA
In reply to # 3735954 by Be Coming
Measure from the center of the wheel to the bottom of the stainless molding.

Oops, that is what I was thinking, but didn't type. So, I fixed it. Thanks for the correction!

Here are some measurements for comparison:

https://www.mgexp.com/article/height.html

JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Thanks for the info, Kelvin.

Measured this morning, as suggested by Carl yesterday, and as you've confirmed today, and have a measurement of 13.5". I guess that gives us a 2" drop if a 1977 MGB has a stock measurement of 15.5".

The previous owner included another set of springs, which I cannot seem to identify. The label on the box has "5-6506" as well as other number combinations. Perhaps the removal of my current springs and an unloaded measurement of them and the extras will clarify the matter.

To reference old-school measuring, the tire/well gap is 1 to 1.5 fingers.

The photos you've included definitely support that we are more than 1" lower.

JustinSchroder Avatar
JustinSchroder Justin Schroder
Lynchburg, VA, USA   USA
1977 MG MGB MkIV "Nigel"
Peter,

Your experience and photos help a great deal in pointing me toward my preference. I am coming to the conclusion that 'Nigel' is down 2" and should be raised to compromise. My only unknown at the moment is how down we are in the back. Looks like you were successful in getting your tie rod and lower control arm angles better that what I have now.

Thanks!

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions




Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster





Join The Club

Sign in to ask questions, share photos, and access all website features

Your Cars

1977 MG MGB MkIII

Text Size

Larger Smaller
Reset Save

Sponsor Links