Hi First time poster here.

I recently bought a used 3 speed (3.03) to replace into my 1970 F-100 XLT 302 3 speed manual. The seller said it came out of a 1975 F-100. The trans has the ID RAB-Y.

The curious thing about this transmission is it appears to have a non-synched 1st gear. It grinds like hell unless you are at a complete stop. The original trans in my 70 had a synchronized 1st gear.

Questions:
1. is RAB-Y in fact from a 1975 F-100?
2. Does RAB-Y have synchonized 1st gear?
3.
Could the shift linkage be off enough to cause it to grind when down shifting into first when moving? Sure seems like an unsynchronized first gear.

Thanks in advance for all responses.

 

Shifter could be out of adjustment .
Clutch may not be releasing correct.
Syncho may be wore out.
May not have syncho .
Can't help on code.___

Oh and welcome newby to F.T.E. , the best forum you will find.




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Thanks Jim!

2nd and 3rd shift just fine up and down, so I can rule out clutch. Could be Rev & 1st shift linkage but like I said sure feels unsynchronized to me on downshift into 1st.

I'm hoping someone can tell me more about RAB-Y.

Thanks!
BP

 

All 303s were all synchro, so your first gear synchro is probably worn out.

I don't find RAB-Y in any list, but that doesn't mean anything. Lots of HEF, RAT, RAN, and a host of others, so RAB could be in there too.

https://www.ford-trucks.com/forums/1...tion-info.html

Mostly they are all the same box, other than the two different ratio sets used. Case length, tailshaft housing length, mounting and shifter mounting holes, and possibly speedo drive gear, maybe speedo output location would be the variables.

 

Thanks for the info! Looks like the trans I bought has an issue with the 1st gear synchro. I'll double check the shift linkage to make siure it is adjusted properly, I had trans installed at a shop. I supplied the trans.

 

Check your shift arm bushings as per ND. They crack and fall out creating hard shifting like not having any syncros.