E36/E46 M14 Bolt Upgrade for (non-M) Polyurethane Front Differential Mount Bushing - Fits E85 and E86

Overview

If you're an avid track racer or drift enthusiast, chances are you may have had to deal with more than a few weak stock bolts, especially those that hold your bushings together! Engineered to withstand the rigors of aggressive driving, this front diff bolt upgrade is a game-changer for those seeking optimal performance and peace of mind for your non-M E36, E46, or Z4.

Many BMW enthusiasts involved in track racing, drifting, or spirited driving have experienced the headache of stock bolts snapping under intense driving conditions. The factory bolts, while suitable for regular driving, are showing their age and often fail to handle the increased stress and forces encountered during high-performance maneuvers. This can lead to catastrophic consequences, leaving drivers stranded and putting their safety at risk.

Say hello to our Garagistic M14 Bolt Upgrade - a tried and tested solution to weak stock diff bolts! Made using class 12.9 steel, it boasts remarkable tensile strength, standing at least 25% stronger than the mediocre medium-strength steel screws used in stock bolts. This impressive enhancement in strength ensures that the bolt can handle the aggressive forces encountered on the track, offering you unmatched durability and performance.

This works as an excellent pairing to our Garagistic Front differential mount bushings, which you can purchase here! (Will also work with other aftermarket front diff bushings)

Why not just get a higher grade bolt?

First of all, you are free to buy a replacement bolt if you think it's just as good. You won't be able to find one that has the correct specs because we obviously tried to do that before we bother to make our own bolt. The closest hardware out there still had a standard nominal shoulder size that left room for the bushing to move. Precision shoulder bolts get expensive and don't have the grade (or cost) to upgrade effectively.

The force that breaks a diff bolt is the allowance of movement between a diff bushing and the hardware that holds it. The sloppier the fit, the more movement is allowed which is what causes the clunk and eventually the bolt failure (see this a lot in clutch-kicking drift cars).

Although a higher grade is an upgrade itself over the OEM bolt, it's the movement between the bolt and diff hole that allows the diff to move. This accelerating force of the diff nose being able to move up and down is what causes bolts to break.

The m14 upgrade is something that's been tried and true by racers and drifters for a long time. We didn't invent that. Although the shoulder being bigger in diameter adds strength itself, the weak point is still the beginning of the threads. What the m14 shoulder in our hardware achieves is that it's a tighter fit into the bushing which stops the diff from moving under heavy load (like clutch kicking etc).

Is this as strong as an m14 bolt all the way through? No. The threads are bigger on that but require you to drill and tap an oem diff that is getting rarer and harder to find. Not to mention the amount of people who mess this up is pretty impressive.

So we simply took the time and money to develop something we think the market would benefit from at a VERY affordable price. A little piece of mind and a slight upgrade over the OEM bolt without the need to drill and tap your diff.

Cliff notes: The tighter fit between the 14mm shoulder of our bolt and the 14mm hole in our bushings is what is helping with sheer strength more than the higher grade of hardware.

Requirements by Chassis

E36 chassis (except Ti) will require 1x of these bolts

E46 (non-M) chassis will require 2x of these bolts

Z4 (non-M) chassis will require 2x of these bolts

Fitment

WHAT MODEL CARS WILL THIS BOLT FIT?

• Fits: E36 chassis (All Models, EXCEPT Ti)
• Fits: E46 chassis (All Models, Except M cars)
• Fits: E85 and E86 Z4 chassis (All Models, Except M cars)
• Replaces: OEM Bolt PN#33176760337