The Ford IB5 5 speed gearbox has been in existence for a substantial amount of time. However there has been several improvements and modifications over the years. This article is going to look at a particular issue with the synchromesh and hub for 1st and 2nd gear.
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Repair Difficulty: Medium / Hard Repair Duration: Average 6 hours Special Tools Required: Basic Gearbox Rebuilding Tools | IB5 5th Gear Puller |
The Ford IB5 gearbox is a regular at Eco Torque. Bearing and gear issues are not uncommon and a particular fault with the hub and synchromesh on 1st/2nd is one we are seeing more of.
Ford Gearbox Fault Symptoms | 1st/2nd
The fault most commonly occurs when the driver tries to select these gears and a loud audible grinding/graunching sound is heard. This can also present itself with a subtle sound but a rumbling/notchy feeling on the gearstick when changing into those gears.
It is possible that a clutch issue may also be present and the root cause of the fault, however if the clutch is worn upon inspection, it is still crucial to investigate the state of the 1st and 2nd gear synchromesh as damage may have occurred.
If you compare the synchromesh on the top to the one on the bottom you can see the wear on the ridged friction surface that grabs the inner part of the synchro. The worn, flattened part no long grips the inner ring correctly, reducing the stopping power of the synchro leading to the hub ring crashing into the gear.
The second compounding issue caused by this damage, is that now the ridges have flattened, it blocks the natural oil way created by this design. This results in a higher temperature during use and and accelerated rate of wear.
Gear Damage
A worn synchromesh, if not dealt with early enough, will result in a level of damage to the gear which will cause a permanent crunching sound, even if the synchromesh rings are replaced.
This is because the mating teeth, as shown below, on the top selective part of the gear lose their sharp triangular shape, it will struggle to locate with its hub ring counterpart. Both the hub ring and gear will show similar wear patterns.
There are currently no official guidelines or measurable values to determine what exact level of wear will result in an issue, so caution is always advised.
Synchromesh faults are varied depending on the model and specific parts required. A strip down of the gearbox is usually required to ascertain the exact repair required.
Frequently Asked Questions
What are the symptoms of the IB5 1st/2nd gear fault?
Most commonly the driver hears a loud grinding or graunching sound when selecting 1st or 2nd gear. It can also present more subtly, as a rumbling or notchy feeling through the gearstick when changing into those gears.
What causes the fault?
It is caused by wear to the hub and synchromesh on 1st and 2nd gear. The ridged friction surface of the synchromesh flattens with wear so it no longer grips the inner ring correctly, reducing the synchro's stopping power and letting the hub ring crash into the gear. The flattened ridges also block the natural oil way in the design, raising temperature and accelerating wear.
Could a worn clutch be involved?
Possibly — a clutch issue may also be present and be the root cause. Even so, if the clutch is found to be worn on inspection, it is still crucial to investigate the state of the 1st and 2nd gear synchromesh, as damage may already have occurred.
What happens if it is left too long?
A worn synchromesh that is not dealt with early enough will damage the gear itself, causing a permanent crunching sound even after the synchromesh rings are replaced. This is because the mating teeth on the selective part of the gear lose their sharp triangular shape and struggle to locate with the hub ring, with both showing similar wear patterns.
How is the fault repaired?
Synchromesh faults vary by model and the specific parts required, so a strip down of the gearbox is usually needed to establish the exact repair. There are no official guidelines or measurable values for the level of wear that will cause an issue, so caution is always advised.
Our workshop is based at:
Eco Torque LTD, Unit 1A Portland Ind Est, Hitchin Road, Arlesey SG15 6SG
01462 835335
info@eco-torque.co.uk
Alternatively the parts for this repair are available below. We strongly recommend all gearbox parts are installed by an experienced professional to avoid further damage.
We are unable to provide installation guides and telephone support at this time.