9 replies to this topic

[Tornado99]

Having some issues keeping the bonnet latched shut on an '88 Mini with stock latch setup.
Tried adjusting the striker/latch plate so the latch pin is centered in the opening. Still got it popping open when hitting some low speed bumps etc.
Took a close look at the latching spring on the release latch and it seems very wimpy. It is flopping about when bonnet is open, not sure how much force it makes on the latch when closed, but might try to improve it or replace with something stronger. Considering replace latching plate and pin for good measure incase there is some wear causing the problem. Any advice on how to set the pin's spring tension? Is more preload helping or hurting the latching?

[dyshipfakta]

I bet the latch itself is worn. Try undoing the bolts and seeing it if will move to the right abit. That fixed the problem I had

[james.o.potter@gmail.com]

The two places where I THINK wear COULD occur here are on the bonnet lock pin

http://www.minispare...es/14A6586.aspx

(See that nice flat side on the shaft end? Is yours just as "rounded" as the "pointy" end.)

Or on the locking "bar" itself:

http://www.minispare...es/AAM1206.aspx


(See that piece that pivots in the photo above that has a somewhat half circle already cut out of it?)

by the way, you haven't said if yours was an "external” release or "internal", and so I'm assuming you have "external" like the picture above with the lever outside at the top of the grill.

The bonnet pin metal is way stronger than the locking lever metal, so IF you have wear, it is likely that it is in the latch and POSSIBLY that half circle has grown too large to securely hold the pin.

But my guess is that it might not be wear, but rather your spring(s), especially since you say the latching spring is "flopping about". On both my original "external" latch and my aftermarket internal conversion that came complete with its own new spring (see below), the springs were pretty taut.

Conversion: http://www.minispare...s/GS130273.aspx

IF it is the latch spring you MIGHT be able to use this cheap later model replacement

http://www.minispare...es/24G3591.aspx

But have you considered that it MIGHT be the pin spring?

http://www.minispare...s/FPQ10001.aspx

This spring's job is to hold the "bullet head" or "acorn" of the bonnet pin tight up against the latch lever.

IF it has gone slack, what COULD be happening is that each time you go through a pothole, the bonnet goes down with the rest of the car and then comes up with enough force to "break past" the EITHER worn latch lever or the "floppy" lever spring.

Finally, one other thing to consider is whether someone has given you a "love tap" while parking in front of you. That DID happen to me and I had to both pull the front panel forward to reposition it AND adjust the bonnet-to-hinges positioning before I got the bonnet latching properly again.

A great test for proper alignment is to lower the bonnet, gently push in the safety catch to allow the bonnet to drop down but NOT latch, and then place your flat hand right above where the bonnet pin would be inside and gently push down against the resistance of the bonnet pin spring. If everything is where it should be, you will hear (and feel through your flat hand) a very satisfying "click" as the latch snaps into place. Then grab the bonnet edge with both hands (like you were about to curl some weights) and move the bonnet down and up and down and up vigorously. It should stay latched. If not, start looking into the latch spring first.

I apologise for so many "IF" and "COULD BE" in my post, but it could be any number of things.

PS: when possible I have found that posting photos of all the parts can help folks here make more confident judgements about what is going on.

Edited by james.o.potter@gmail.com, 03 October 2021 - 04:09 AM.

[Tornado99]

Thanks for the advice. Will be taking it apart today, got a mini club meet up tomorrow and want the bonnet to stay closed.

It is the external type release. I think I'll try to put tension on the latch spring as it is floppy in the anchoring holes when bonnet is open

Edited by Tornado99, 02 October 2021 - 05:12 PM.

[Tornado99]

Ok, had everything off, striker and pin. Cleaning up locking plate noted there was a slight chamfer to the edge where it engages with the pin shoulder. This, with a slight bit of sloppiness on the latching pivot joint, could make the pin slip off the latch, especially if the latch spring was not giving much force. I lightly ground down the latching surface so it was back at a 90 degree edge at ther engagement surface. Found it was pretty easy to trim back a few coils of the spring using dremel cut off disc, then bend up the end coil and form it to similar shape and angle as original using needle nose pliers. Effectively making spring shorter overall. It now has some tension on latch when pin is not engaged, but still easy to move latch when opening. got it re-installed, getting pin as centered as possible in striker plate opening using a bit of masking tape over the hole and a dab of grease on pin tip, slowly lowering bonnet until pin contacted tape, leaving a grease spot to help determine where it was, adjusting plate accordingly.

Seems to be ok but will not know until some bumpy road miles.

Edited by Tornado99, 02 October 2021 - 07:55 PM.

[Ethel]

They can do this if they rust through at the end of the panel by the wing.

[Tornado99]

They can do this if they rust through at the end of the panel by the wing.

Not likely a rusting issue. Car is a full restore, no rust anywhere as far as I've found. 

[james.o.potter@gmail.com]

Sounds like you might have solved the problem with those two adjustments you've made - nicely done.

 

And as you say: putting some miles on it will tell for sure.

 

Good luck!

[Tornado99]

After todays Mini club drive, over four hrs in the car, not a pop open in sight. Think we can declare victory on this issue.
Now on to the next one, my Smiths Tacho started fluctuating wildly on this trip, been rock steady since installed last year. Will start a new thread.

[james.o.potter@gmail.com]

Congrats!