I am working hard to make Project Beach Cruiser drive better on the highway. Looking for wisdom from the manual-steering 40 crowd specifically, because I think the setup is different than one with power steeting.
Background: ‘71 FJ40, manual steering (stock box), front is stock height. The front end is about as tight as they come right now: new tie rod ends, new leaf spring bushings, new wheel bearings, new trunnion bearings. So I’m not chasing slop in worn parts; this is a geometry/spec question.
I want to be clear up front: I love how this thing drives with the manual box and I want to keep it manual. No interest in power steering unless I start actually wheeling it more, which isn’t the plan. This is not a daily driver; It’s a weekend top-down coffee-run truck, and I want it to feel right when I do drive it.
I run longer lift shackles in the rear to offset some sagged leaf springs. Worth noting: before the shackles the truck sat slightly nose-high; now it’s perfectly level.
Tires are Falken Wildpeak M/T LT235/85R16 on City Racer 16x5.5 wheels (3.25” backspace, same as the OEM 15”).
Here’s the progression that’s got me scratching my head:
Original setup from 2017: 31” Goodyears on FJ60 wheels. Heavy to turn in parking lots, but amazing on the highway. I could run it as fast as it’d go, and was always surprised how well it cruised. Used to pass everyone down Highway 1 near Santa Cruz cruising 75+. This is my benchmark and nothing since has come close.
Current setup: 235/85R16 on the City Racer wheels. In-town steering got way lighter/better. The steering feel is ‘right’ but it now wanders on the road and isn’t comfortable above 55.
I replaced the tie rod ends and added a Bilstein stabilizer last weekend Post-tie-rod, pre-alignment it tracked straighter and felt more secure. Meaning it was better than the new-wheel setup had been, but still not as stable as the old 31”/FJ60 combo. I hand-set toe to ~1/4” with a TMR jig.
After the tie rod ends I took it for a proper alignment. When driving home I immediately noticed and it came back worse. Now it’s uncomfortable at high speed and a little darty at low speed. The shop pulled toe from 0.43” total down to 0.17” (their window was 0.12”–0.20”), and caster reads ~0.8–0.9°. Sheet attached.
My questions:
Background: ‘71 FJ40, manual steering (stock box), front is stock height. The front end is about as tight as they come right now: new tie rod ends, new leaf spring bushings, new wheel bearings, new trunnion bearings. So I’m not chasing slop in worn parts; this is a geometry/spec question.
I want to be clear up front: I love how this thing drives with the manual box and I want to keep it manual. No interest in power steering unless I start actually wheeling it more, which isn’t the plan. This is not a daily driver; It’s a weekend top-down coffee-run truck, and I want it to feel right when I do drive it.
I run longer lift shackles in the rear to offset some sagged leaf springs. Worth noting: before the shackles the truck sat slightly nose-high; now it’s perfectly level.
Tires are Falken Wildpeak M/T LT235/85R16 on City Racer 16x5.5 wheels (3.25” backspace, same as the OEM 15”).
Here’s the progression that’s got me scratching my head:
Original setup from 2017: 31” Goodyears on FJ60 wheels. Heavy to turn in parking lots, but amazing on the highway. I could run it as fast as it’d go, and was always surprised how well it cruised. Used to pass everyone down Highway 1 near Santa Cruz cruising 75+. This is my benchmark and nothing since has come close.
Current setup: 235/85R16 on the City Racer wheels. In-town steering got way lighter/better. The steering feel is ‘right’ but it now wanders on the road and isn’t comfortable above 55.
I replaced the tie rod ends and added a Bilstein stabilizer last weekend Post-tie-rod, pre-alignment it tracked straighter and felt more secure. Meaning it was better than the new-wheel setup had been, but still not as stable as the old 31”/FJ60 combo. I hand-set toe to ~1/4” with a TMR jig.
After the tie rod ends I took it for a proper alignment. When driving home I immediately noticed and it came back worse. Now it’s uncomfortable at high speed and a little darty at low speed. The shop pulled toe from 0.43” total down to 0.17” (their window was 0.12”–0.20”), and caster reads ~0.8–0.9°. Sheet attached.
My questions:
- What toe-in do you actually run on a manual 40? Book is ~1–5mm but mine clearly liked ~1/4”. Is 0.20”–0.25” total reasonable, or am I chewing tires for nothing?
- Caster — how much is too much for manual steering? I build offroad trucks with 4.5–6° all the time, but those have power steering. I know caster trades directly against effort on a manual box, and I don’t want to ruin the light steering I just gained. Tempted to throw 3° shims at it to land ~3.5–4° total. Is that livable on a manual 40, or will I regret it? What’s your sweet spot for a manual truck?
- Tire diameter — stock these trucks were designed around roughly a 27” tire and I’m now on a ~32” (235/85R16). For those of you running 32s or 33x9.5’s on a manual 40, did you find you needed more caster and/or more toe than book to settle it down at speed? Trying to figure out how much of my wander is “wrong alignment numbers” vs “stock geometry doesn’t love a larger tire.”
