We are seeing an increasing amount of Kia & Hyundai 6 speed models with a common gear crunching issue. This can happen in 3rd, 4th, 5th and 6th gear, or a combination of them.
More details in the article as well as repair solutions.
Introduction
We have seen a common issue arising with a particular gearbox fitted to Hyundai & Kia models effecting gear selection. The issue results in an audible grinding noise when trying to select gears. After investigating we found the following issue.
Symptoms & Repairs
The fault most commonly occurs when the driver tries to select a gear and a loud audible grinding/graunching sound is heard. This can be in 3rd, 4th, 5th and 6th gear, or a combination of those listed.
It is possible that a clutch issue may also be present and the cause, however it is not common to have issues in just the high gears, it is normally the opposite way round, with reverse, 1st and 2nd being difficult to select.
After stripping the units we discovered and interesting fault with the synchromesh rings.
If you compare the synchromesh on the left to the one on the right you can see the stop tab has broken off. This tab locates within the hub with a small amount of play and allows the gear to match the hub speed and stops the synchromesh simply rotating with the gear once it has gripped.
The tabs had made their way around the gearbox luckily not coming into contact with gears and bearings.
The synchromesh on gears 3, 4, 5 and 6 are all of the same design and same part number. This part has thus superseded and a new design of synchro replaces this in order to prevent the issue happening again.
We would recommend changing all four of the old design of synchro if the transmission is removed to prevent costly repairs at a later date.
Models affected
- Kia Sportage | 1700cc
- Kia Ceed | 1400cc 1600cc
- Kia Rio | 1400cc 1600cc
- Kia Rio | 1400cc
- Kia Venga | 1400cc 1600cc
- Hyundai I30 | 1400cc 1600cc
- Hyundai IX35 | 1700cc
- Hyundai Tucson | 1700cc
Frequently Asked Questions
Which gears are affected by the Kia and Hyundai 6-speed crunching fault?
Most commonly a loud grinding or graunching noise when selecting 3rd, 4th, 5th or 6th, or a combination. It is unusual to have problems only in the higher gears — normally it is reverse, 1st and 2nd that become difficult — which helps distinguish this fault.
What actually causes the crunching?
On stripping the units we found the stop tab had broken off the synchromesh ring. That tab locates in the hub and lets the gear match the hub speed; with the tab gone the synchro cannot do its job and the gear crunches on selection.
Could it be a clutch problem instead?
A clutch issue may also be present and contributing. However, a clutch fault typically makes reverse, 1st and 2nd hard to select rather than just the high gears, so crunching confined to 3rd–6th points more strongly to the synchromesh fault.
Is there an improved part, and should all the synchros be replaced?
The synchromesh on 3rd–6th are all the same design and part number, and this part has been superseded by a new design. If the transmission is already removed we recommend changing all four old-design synchros to avoid costly repeat repairs.
Which Kia and Hyundai models are affected?
Kia Sportage (1700cc), Ceed (1400/1600cc), Rio (1400/1600cc) and Venga (1400/1600cc); Hyundai i30 (1400/1600cc), ix35 (1700cc) and Tucson (1700cc).
Parts for this repair
We stock the parts for this job and ship them from our Arlesey workshop. Not sure which gearbox you have? Send us your registration and we will confirm it before you order.
- M6CF3-1 6-speed gearbox parts — 16 lines in our M6CF3-1 (6 Speed) range
- Manual gearbox parts — 228 lines in our Manual Gearbox Parts range
- Manual gearbox bearings — 105 bearing lines listed
- Gearbox oil — 117 oil lines listed
Contact Eco Torque Today
Tel: 01462 835335
Email: info@eco-torque.co.uk
Eco Torque Ltd, Unit 1A Portland Industrial Estate, Hitchin Road, Arlesey, United Kingdom, SG15 6SG
18 comments
I have a problem with gear crunching when going into 6th gear only what is the cost of this repair ?
I have Kia sportage 17 Diesel 2014 I have the problem going into fourth and fifth gear how much does it cost roughly to to have the rings exchanged, thanks