The original 5 speed manual in my 2013 Fiesta SE 1.6 DOHC never liked to downshift into 1st. I had to be at a crawl below 5mph. I have read of several complaints from other people. I just installed a used IB/5 Transmission. It has no problem shifting into 1st, even from 10MPH. Very smooth. I don't know if this IB/5 came from a Fiesta, or something else. That transmission was put in the Focus and other cars. Was it only the Fiesta that had this issue? If so did it start at a certain year model?

 

No, all IB5s are a bit lumpy, worsened with mileage and/or abuse

It's based a very old gearbox

Why would anyone want to change 'Down' in to first gear at a speed of more than 4 MPH ? 🤔

On 8/1/2025 at 3:03 AM, unofix said:

Why would anyone want to change 'Down' in to first gear at a speed of more than 4 MPH ? 🤔

Consider this,you have slowed down to 2nd for a red light. It has changed to green. You notice a semi is approaching at speed behind you. Driver is not paying attention or reading a text. He is not slowing down. Your revs are too low to accelerate in 2nd so you need to get into 1st to avoid being rear ended. Not being able to shift into 1st from 15mph or lower is just stupid. Makes you wonder why they even put synchro on 1st if it is not useful. At least I could match revs and get it into 1st w/not synchro 1st.

The reason this box is designed not to shift into 1st above a crawl is because it was originally a 4speed. The added a 5th gear at the tail end and that much more rotating mass was to much for the 1st gear synchro to deal with so they did a mod preventing you from shifting to 1st above 5mph.

I have never had a transmission that I could shift into 1st at a reasonable speed. That includes ones made in the 50's to the late 90's.

I finally disassembled the IB/5 transmission. Problem was that it would sometimes pop out of 1st with a bang. If not, I could accelerate under full power and stay in gear. I suspect there may be a spring loaded ball bearing that is part of that 1st gear synchro assembly and that is what is causing 1st gear to pop out of gear sometimes. I developed a sense of when it would happen and just take off in 2nd. 

I  would not be surprised if the synchro rings did not show much wear. I could shift into 1st at a crawl with no grinding. Did not find a lot of filings on the magnet. The gearbox seemed very clean inside.

Are there any special tools I need to disassemble the mainshaft assembly to get to the 1st gear synchro?

 

I rebuilt this transmission, learning a lot about it. Poor Design. Before, it would pop out of 1st when taking off. After rebuilding it with new 1st/2nd synchro assy. It will sometimes still pop out of 1st on take off. I think the reason is that I bent the shifter fork one time while trying to shift into First at slow enough speed that that the engine did not have enough torque in 2nd to accelerate fast enough to avoid being rear ended by somebody going too fast and not paying attention.

I now move the shifter rapidly from 2nd to 1st to insure that the dogs fully engage into the side of 1st gear. I will rebuild again replacing that shifter fork so that the synchro unit will travel far enough forward for the dogs to engage all the way.

It is said that the IB/5 is designed to not shift into 1st above a crawl to avoid something catastrophic happening. That's BS. I can shift to second at 15 MPH so nothing is going to happen at that speed if I shift from 2nd to 1st at that speed.

Besides the addition of the 5th gear adding additional rotational force for the 1st synchro, reverse gear was cludged onto the 1st/2nd gear synchro unit adding more mass for the synchro unit to deal with. I doubt if the 4 speed version would shift into 1st well. I am surprised that the Germans would engineer something like that. Shame on GETRAG.

In 60+ years driving I have never had trouble shifting to 1st with a synchronized transmission. That's VW Beetle, TR3B, TR4, Opel Kadet, Datsun's, Toyota's, BMW's, Escort's, a list too long to enumerate.

It is sad that It is very difficult to buy a new car with a manual transmission for under $100,000. Most of the automatics are now designed in Germany and are not serviceable or repairable.

Edited February 16Feb 16 by borgward
typo